IT and Applications (Foundation of Information Technology)

Information technology affects business in several ways:

• It speeds up operations and reduces costs through automation.
• It improves communication and collaboration through email, video conferencing and the internet.
• It opens new markets through e-commerce and online marketing.
• It supports better decisions through data analysis and management information systems.
• It improves customer service and record keeping, while also bringing security risks and a need for skilled staff.

Sequential data processing is a method in which transactions are collected and processed one after another in a fixed order, usually the order of a key field, with records read from a file from start to end. Payroll processing from a sorted file or magnetic tape is an example.

Encryption is the process of converting readable data (plaintext) into an unreadable coded form (ciphertext) using an algorithm and a key, so that only authorised parties holding the correct key can decrypt and read it. It protects data during storage and transmission.

Primary memory (main memory) is the memory directly accessed by the CPU. It holds the programs and data currently in use. It is fast, has limited capacity, and is directly connected to the processor.

Types of primary memory

(a) RAM (Random Access Memory): read/write, volatile memory that loses its contents when power is off. It is of two types:

• SRAM (static RAM): uses flip-flops, faster, more costly, needs no refreshing; used for cache.
• DRAM (dynamic RAM): uses capacitors, slower, cheaper, needs periodic refreshing; used as main memory.

(b) ROM (Read Only Memory): non-volatile memory whose contents are permanent, used to store the boot program (BIOS). Types are:

• PROM: programmable once by the user.
• EPROM: erasable with ultraviolet light and reprogrammable.
• EEPROM: erasable electrically and reprogrammable; flash memory is a related type.

(c) Cache memory: a small, very fast memory between the CPU and RAM that stores frequently used data and instructions to speed up processing.

Network topology is the physical or logical arrangement of the nodes (computers and devices) and links in a computer network.

Types of topology

(a) Bus: all nodes connect to a single common cable (backbone). It is cheap and easy to install, but a break in the cable stops the whole network and performance falls as nodes increase.

(b) Star: every node connects to a central hub or switch. It is easy to manage and a faulty node does not affect others, but failure of the central device brings down the network.

(c) Ring: each node connects to exactly two neighbours forming a closed loop, and data travels in one direction (often with a token). It gives equal access, but one failure can break the ring.

(d) Mesh: every node connects to every other node. It is highly reliable and fault tolerant, but costly and complex to install.

(e) Tree (hierarchical): star networks connected to a bus backbone in a hierarchy. It is scalable, but depends on the root and backbone.

(f) Hybrid: a combination of two or more topologies.

A database model defines how data is structured, stored and related. The main types are:

• Hierarchical model: data is arranged as a tree of parent and child records; each child has only one parent (one-to-many).
• Network model: data is arranged as a graph where a record can have multiple parents, allowing many-to-many relations.
• Relational model: data is stored in tables (relations) of rows and columns, linked by keys. It is the most widely used (MySQL, Oracle, SQL Server) and is queried using SQL.
• Object-oriented model: data is stored as objects with attributes and methods, supporting inheritance.
• Entity-relationship model: a conceptual model showing entities and their relationships, used in database design.

Multimedia is the integrated use of several media such as text, graphics, audio, video and animation in a computer-based presentation, controlled and delivered interactively. Examples are educational software, games and websites.

Elements of a multimedia system

• Text: the basic element used for titles, headings and content, in different fonts and sizes.
• Graphics (images): pictures, drawings and photographs that illustrate information.
• Audio: speech, music and sound effects, stored in formats such as MP3 and WAV.
• Video: recorded moving pictures with sound, in formats such as MP4 and AVI.
• Animation: the simulation of motion by displaying a series of images in sequence.
• Interactivity: links and controls that let users navigate and control the content.

An operating system (OS) is system software that manages computer hardware and software resources and provides an interface between the user and the computer. Examples are Windows, Linux, macOS and Android.

Functions of an operating system

• Process management: creating, scheduling and terminating processes, and allocating the CPU.
• Memory management: allocating and freeing main memory for programs, including virtual memory.
• File management: creating, storing, organising, protecting and retrieving files and directories.
• Device management: controlling input/output devices through drivers.
• Security and protection: passwords, user accounts and access control.
• User interface: providing a command line or graphical interface.
• Resource allocation, error detection and job accounting.

Types of operating system

• Batch operating system: similar jobs are collected and processed in batches without user interaction.
• Multiprogramming operating system: several programs are kept in memory and the CPU switches between them to increase utilisation.
• Time-sharing (multitasking) operating system: the CPU time is divided into slices so that many users or tasks share it interactively.
• Multiprocessing operating system: uses two or more CPUs in one computer to execute tasks in parallel.
• Real-time operating system: gives responses within strict time limits, used in missile control, medical and industrial systems.
• Distributed operating system: manages a group of independent networked computers so they appear as one system.
• Network operating system: provides file, printer and resource sharing to computers on a network (Windows Server).
• Single-user and multi-user operating systems: serve one user or many users at a time.
• Mobile operating system: designed for smartphones (Android, iOS).

An operating system (OS) is system software that manages computer hardware and software resources and provides an interface between the user and the computer. Examples are Windows, Linux, macOS and Android.

Types of operating system

• Batch operating system: similar jobs are collected and processed in batches without user interaction.
• Multiprogramming operating system: several programs are kept in memory and the CPU switches between them to increase utilisation.
• Time-sharing (multitasking) operating system: the CPU time is divided into slices so that many users or tasks share it interactively.
• Multiprocessing operating system: uses two or more CPUs in one computer to execute tasks in parallel.
• Real-time operating system: gives responses within strict time limits, used in missile control, medical and industrial systems.
• Distributed operating system: manages a group of independent networked computers so they appear as one system.
• Network operating system: provides file, printer and resource sharing to computers on a network (Windows Server).
• Single-user and multi-user operating systems: serve one user or many users at a time.
• Mobile operating system: designed for smartphones (Android, iOS).

Functions of an operating system

• Process management: creating, scheduling and terminating processes, and allocating the CPU.
• Memory management: allocating and freeing main memory for programs, including virtual memory.
• File management: creating, storing, organising, protecting and retrieving files and directories.
• Device management: controlling input/output devices through drivers.
• Security and protection: passwords, user accounts and access control.
• User interface: providing a command line or graphical interface.
• Resource allocation, error detection and job accounting.

Computers are classified by size as:

• Supercomputers: the largest and fastest, used for weather forecasting and scientific research.
• Mainframe computers: large machines serving hundreds of users at once, used in banks and insurance companies.
• Minicomputers: mid-sized multi-user machines, used by medium businesses and departments.
• Microcomputers: small single-user computers such as desktops, laptops, tablets and smartphones.

Auxiliary memory (secondary or backup memory) is non-volatile, permanent storage of large capacity that holds programs and data not currently in use by the CPU. It is slower and cheaper than primary memory. Examples are hard disks, SSDs, CDs/DVDs, pen drives and magnetic tapes.

Utility software is system software that helps analyse, configure, optimise and maintain the computer. Examples are antivirus programs, disk defragmenters, backup tools, file compression tools (WinZip) and disk cleaners.

A protocol is a set of rules and conventions that governs how data is formatted, transmitted and received between devices in a computer network, so that different devices can communicate. Examples are TCP/IP, HTTP, FTP and SMTP.

A search engine is a web-based software system that searches the internet for information matching keywords entered by the user and displays the results as a ranked list of links. Examples are Google, Bing and Yahoo.

Data mining is the process of analysing large databases or data warehouses to discover hidden patterns, relationships and useful knowledge using statistical and machine learning techniques. Businesses use it for customer profiling, market basket analysis and fraud detection.

The main characteristics of a computer are:

• Speed: performs millions of operations per second.
• Accuracy: gives error-free results if the input and program are correct.
• Diligence: works for long hours without tiredness or loss of concentration.
• Versatility: can perform many different kinds of tasks.
• Storage capacity: stores large amounts of data permanently and retrieves it quickly.
• Automation: once a program is loaded, it works on its own without human intervention.
• No intelligence (IQ): it does only what it is instructed to do.

Fourth generation computers (1971 to present) have these characteristics:

• They use microprocessors built with LSI and VLSI integrated circuits.
• They are small, cheap, fast and reliable, which made personal computers possible.
• They use semiconductor memory (RAM and ROM) with large capacity.
• They use high-level languages and graphical user interfaces, with operating systems such as MS-DOS and Windows.
• They support networking, the internet, and input devices such as the mouse and keyboard.
• Examples are IBM PC, Apple Macintosh and modern laptops.

Cyber security is essential because organisations and individuals store and transmit sensitive data online.

• Protects data: keeps personal, financial and business information confidential and safe from theft.
• Prevents attacks: guards against viruses, ransomware, phishing and hacking that cause loss and downtime.
• Business continuity: keeps systems running, protecting reputation and customer trust.
• Financial protection: avoids the cost of fraud, recovery and legal penalties.
• Protects critical infrastructure: banks, government and telecom services depend on secure systems, and e-commerce and e-governance need trust.

The central processing unit (CPU) is the brain of the computer. It interprets and executes instructions and controls all other parts. It has three main components:

• Arithmetic Logic Unit (ALU): performs arithmetic operations (add, subtract, multiply, divide) and logical operations (comparison, AND, OR, NOT).
• Control Unit (CU): fetches instructions from memory, decodes them, and directs the other units to execute them.
• Registers: small, very fast storage locations inside the CPU holding data and instructions being processed (such as accumulator, program counter, instruction register).

CPU speed is measured in gigahertz (GHz). Modern CPUs are built as a single microprocessor chip.

Artificial intelligence (AI) enables machines to simulate human intelligence such as learning, reasoning and decision making. Its role in business includes:

• Customer service: chatbots and virtual assistants answer queries 24 hours a day.
• Marketing and sales: personalised recommendations, customer segmentation and targeted advertising.
• Decision making: predictive analytics for demand, sales and risk forecasting.
• Operations: automation of repetitive tasks, inventory management and quality control, reducing cost and errors.
• Finance and security: fraud detection and credit scoring.
• HR: screening of applications.

E-governance is the use of ICT to deliver government services and information to citizens, businesses and government bodies. It is necessary because:

• Transparency and accountability: online records reduce corruption and discretion.
• Efficiency: faster processing, less paperwork and lower administrative cost.
• Citizen convenience: services such as tax filing, bill payment and certificates are available anytime and anywhere, saving time and travel.
• Participation: citizens can give feedback and take part in decision making.
• Better coordination between government agencies through shared data, and wider reach to remote areas.

Hard copy output devices produce a permanent, physical record of output on paper or other physical media, for example printers and plotters.

Soft copy output devices produce temporary, non-physical output that is displayed or heard and lost when the device is switched off, for example monitors, projectors and speakers.

Impact printers form characters by striking an inked ribbon against the paper (dot matrix, daisy wheel, line printer).

Merits of impact printers

• Can print carbon copies (multiple copies in one pass).
• Cheap to run, and the ribbon is inexpensive.
• Durable and can work in dusty, harsh environments.
• Suitable for continuous stationery.

Demerits of impact printers

• Noisy.
• Slow with low print quality.
• Poor graphics and limited colour and fonts.

Non-impact printers form characters without striking the paper, using ink spray, heat or laser (inkjet, laser, thermal).

Merits of non-impact printers

• Quiet.
• Fast with high print quality.
• Good graphics, fonts and colour.

Demerits of non-impact printers

• Cannot make carbon copies.
• Costly cartridges, toner and consumables; higher purchase cost, especially for laser.
• Ink may smudge on wet paper (inkjet).

The characteristics of a computer are:

• Speed: performs millions of operations per second.
• Accuracy: gives error-free results if the input and program are correct.
• Diligence: works for long hours without tiredness or loss of concentration.
• Versatility: can perform many different kinds of tasks.
• Storage capacity: stores large amounts of data permanently and retrieves it quickly.
• Automation: once a program is loaded, it works on its own without human intervention.
• No intelligence (IQ): it does only what it is instructed to do.

Cache memory is a small, very fast memory placed between the CPU and main memory (RAM) that stores frequently used data and instructions, so the CPU can access them faster and need not wait for the slower RAM.

System software is the set of programs that manage and control computer hardware and provide a platform for running application software. Examples are operating systems, language translators (compiler, interpreter, assembler), device drivers and utility programs.

A protocol is a set of rules and conventions that governs how data is formatted, transmitted and received between devices in a computer network, so that different devices can communicate. Examples are TCP/IP, HTTP, FTP and SMTP.

FTP (File Transfer Protocol) is used to transfer files between a client and a server over a network or the internet, for uploading files to and downloading files from a web server or remote computer.

A database management system (DBMS) is software that allows users to create, define, store, retrieve, update and manage data in a database, while controlling security, integrity and concurrent access. Examples are MySQL, Oracle, MS Access and SQL Server.

Cloud computing is the delivery of computing services such as storage, servers, databases, software and networking over the internet on demand, usually on a pay-as-you-use basis, without owning the physical infrastructure. Examples are Google Drive, AWS and Microsoft Azure.

A general-purpose computer can perform a wide variety of tasks by running different programs. Its parts are shown in the block diagram below.

 Input unit --> [ CPU: Control Unit + ALU ] --> Output unit
                     ^          |
                     |          v
              Main memory <--> Secondary storage

• Input unit: accepts data and instructions (keyboard, mouse) and converts them to machine form.
• Central processing unit: the control unit directs operations and the ALU performs arithmetic and logic.
• Memory unit: main memory holds data and programs being processed; secondary storage keeps them permanently.
• Output unit: presents results to the user (monitor, printer).

Third generation computers (1965 to 1971) have these characteristics:

• They use integrated circuits (ICs) instead of transistors.
• They are smaller, faster, cheaper, more reliable and consume less power than the second generation.
• They use high-level languages such as FORTRAN, COBOL, BASIC and Pascal.
• They introduced operating systems, multiprogramming and time sharing.
• They use keyboards and monitors for input and output, and semiconductor memory.
• Examples are IBM 360 series and PDP-8.

Cyber law is essential because crime and disputes now occur in cyberspace, where ordinary laws are often insufficient.

• It defines and punishes cyber crimes such as hacking, identity theft, online fraud and spreading malicious software.
• It gives legal recognition to electronic records and digital signatures, which enables e-commerce and e-governance.
• It protects privacy and intellectual property such as software and online content.
• It protects users and consumers, and gives a basis for resolving disputes.
• It builds trust in online transactions. In Nepal the Electronic Transactions Act, 2063 serves this purpose.

A bus is a set of parallel wires or lines that carries data and signals between the components of a computer (CPU, memory and I/O devices). The width of a bus (such as 32 or 64 bits) affects speed. There are three types:

• Data bus: carries data between CPU, memory and I/O devices. It is bidirectional.
• Address bus: carries the memory address of the location to be read or written. It is unidirectional, from the CPU, and its width decides the maximum addressable memory.
• Control bus: carries control and timing signals (read, write, interrupt, clock) that coordinate activities.

Artificial intelligence (AI) is the branch of computer science that builds machines and software able to perform tasks requiring human intelligence, such as learning, reasoning, problem solving and understanding language.

Application areas

• Healthcare: disease diagnosis, medical imaging and drug discovery.
• Business and finance: chatbots, fraud detection, credit scoring and forecasting.
• Education: personalised learning and automated grading.
• Robotics and manufacturing: industrial robots and quality inspection.
• Transport: self-driving vehicles and traffic management.
• Language and speech: translation, voice assistants such as Siri and Alexa.
• Games, agriculture and security: game playing, crop monitoring and face recognition.

IP address: an Internet Protocol address is a unique numeric address assigned to each device on a network, used to identify and locate it. IPv4 uses 32 bits written as four decimal numbers separated by dots, for example 192.168.1.10. IPv6 uses 128 bits.

Benefits of using a domain name

• It is easy to remember (such as google.com) compared with numeric IP addresses.
• It gives a business a recognisable identity and brand on the web.
• The IP address of a server can change without users noticing, since DNS maps the name to the new address.
• It lets email addresses use the organisation's name and adds credibility.
• It helps search engine visibility.

Transmission media are the physical paths or channels through which data travels from sender to receiver.

Guided (wired) media carry signals along a physical cable that guides them from one point to another.

• Twisted pair cable: pairs of insulated copper wires twisted together to reduce interference. It is cheap and used in telephone and LAN cabling. It is UTP (unshielded) or STP (shielded). Its range and speed are limited.
• Coaxial cable: a copper core with insulation, a metal shield and an outer jacket. It has higher bandwidth and less interference than twisted pair, and is used in cable TV and older Ethernet networks.
• Optical fibre cable: thin glass or plastic strands carrying light pulses. It has very high speed and bandwidth, low loss, long distance and no electromagnetic interference, but is costly and harder to install.

Unguided (wireless) media transmit signals through air or space without a physical conductor.

• Radio waves: omnidirectional, pass through walls; used in radio, FM and Wi-Fi.
• Microwaves: line-of-sight, high-frequency signals sent between towers; used in mobile and point-to-point links.
• Satellite communication: signals relayed via satellites in orbit, for wide-area coverage (TV, GPS, VSAT).
• Infrared: short-range line-of-sight communication, such as remote controls.
• Bluetooth and other short-range radio links connect nearby devices.