Basics of Information Technology

Understand how computer hardware, software, networks and multimedia work together to receive, process, store and communicate information.

Syllabus concepts

Computer system

A computer system combines input, processing, memory/storage and output. The CPU processes instructions; input devices send data; output devices present results.

Memory and storage

RAM is working memory and loses its contents when power is off. ROM stores firmware instructions. Secondary storage such as a hard disk or flash drive keeps files for later use.

Software

System software such as an operating system manages hardware and files. Device drivers help the operating system communicate with particular devices. Application software helps users perform tasks, including mobile apps.

Networks and cloud

PAN covers a person’s nearby devices; LAN a local area; MAN a metropolitan area; WAN a large geographic area. Wi‑Fi and Bluetooth are wireless technologies with different typical range and uses. Cloud services store or process resources on remote systems; public and private cloud differ in access and control.

Multimedia

Images, audio, video and animation combine text and media to communicate information. Choose a suitable format and use media responsibly.

Worked example

A student types a report, edits it, saves it to a flash drive and prints it. The keyboard is input, the CPU processes commands, RAM supports current work, the flash drive is secondary storage and the printer is output.

Practice questions with answers

1. Which memory is normally volatile: RAM or ROM?

RAM is volatile: its working contents are lost when power is switched off.

2. A school connects computers within one building. Which network type best fits?

A LAN, because it connects devices in a limited local area.

3. Is a web browser system software or application software?

It is application software used to access web pages.

Practical task and self-check

Create a small sample task using this unit’s tools. Save it, reopen it, inspect the result and explain one choice you made.

Can I explain the key terms without memorising a paragraph?
Can I demonstrate the task and describe the steps?
Have I checked accuracy, privacy and file organisation?

These are original revision notes aligned to the CBSE Class IX 2026–27 curriculum. Use them with your prescribed NCERT book and your teacher’s directions. Official CBSE syllabus