What is ICT? Hardware, software and how a computer works
ICT stands for information and communication technology: computers, phones, tablets, the internet and the programs that run on them.
- Hardware: the parts you can touch (screen, keyboard, processor).
- Software: the programs and apps. The operating system (such as Windows, macOS, Android, Linux) runs the device; applications do tasks (word processor, browser, video editor).
Every computer follows input → process → output, plus storage:
- Input: keyboard, mouse, touch screen, microphone, camera.
- Process: the CPU follows instructions. RAM is short-term working memory that is cleared when power is off.
- Output: screen, speakers, printer.
- Storage: SSD, hard disk, USB drive, memory card, cloud. These keep data when power is off.
Storage units and file types
Computers store everything as bits (0 or 1). 8 bits = 1 byte, about one letter.
- 1 kilobyte (KB) = 1000 bytes: a short text message.
- 1 megabyte (MB) = 1000 KB: a phone photo is about 3 MB.
- 1 gigabyte (GB) = 1000 MB: a film is about 2 GB.
- 1 terabyte (TB) = 1000 GB: a large hard disk.
(Some systems count in 1024s and write KiB, MiB, GiB.)
The file extension after the dot tells the type: .docx or .odt (document), .pdf (fixed document), .jpg or .png (image), .mp3 (sound), .mp4 (video).
Organising files, the cloud and learning platforms
Files and folders
Keep a simple tree: School › Science › Light. Use clear file names with a date: 2026-10-01_light-notes. Avoid 'final-final2'. Delete or archive what you no longer need.
Cloud storage
The cloud means storing files on internet servers run by a company. You can open them from any device and share links. It needs internet and a safe account, and you should check who can see each shared file.
Learning platforms
A learning platform (learning management system, such as Google Classroom, Moodle or Microsoft Teams for education, or India's DIKSHA) is a website or app where teachers post lessons and tasks, and students submit work, take quizzes, get feedback and talk in class groups. Check it daily, note deadlines, name submissions clearly and keep a copy of what you submit.
Storing information safely: backups and passwords
Backups: the 3-2-1 rule
Keep 3 copies of important work, on 2 kinds of storage (for example laptop + USB drive), with 1 copy away from home (the cloud). Then a lost phone, broken laptop or even a fire cannot wipe it out.
Protect your accounts
- Use a long passphrase: 4 random words like river-mango-cloud-piano. Length matters most.
- Use a different password for each important account; a password manager helps.
- Turn on two-step verification (a code on your phone as well as the password).
- Never share passwords; log out on shared computers.
- Install updates: they fix security holes.
- Beware of phishing: fake messages asking for your password.
Creative digital projects
ICT lets you create, not only consume: a slide show, a short video, a podcast, a simple website, a poster or a program. A good project follows steps: plan (audience and purpose), gather (your own photos, or ones with a licence that allows reuse, and credit sources), make, test with a friend, improve and share safely.
Try it: make a 'School' folder with one sub-folder per subject on your device or cloud drive, rename three files with the date-topic pattern, and copy one important file to a second place. You have started a 3-2-1 backup.
Key formulas and definitions
- Input → Process → Output, + Storage
- 8 bits = 1 byte
- 1 KB = 1000 B; 1 MB = 1000 KB; 1 GB = 1000 MB; 1 TB = 1000 GB
- Backups: 3 copies, 2 kinds of storage, 1 off-site
- Possible passwords = (characters to choose from)^(length)
- File name: date_topic (e.g. 2026-10-01_light-notes)
Worked examples
1. A phone has 64 GB of free space. About how many 4 MB photos can it hold?
64 GB = 64 000 MB. 64 000 ÷ 4 = 16 000 photos (roughly).
2. Classify each as input, output, process or storage: microphone, printer, CPU, USB drive.
Microphone: input. Printer: output. CPU: process. USB drive: storage.
3. A PIN uses 4 digits (0–9). How many PINs are possible? How many with 6 digits?
4 digits: 10^4 = 10 000. 6 digits: 10^6 = 1 000 000. Two more digits make it 100 times harder to guess.
Common mistakes
- Keeping only one copy of important work. One fault can lose it all; use 3-2-1.
- Thinking RAM keeps files. RAM is cleared when the power goes; save to storage.
- Using a short password with your name or birthday. Length and randomness matter.
- Naming files 'new', 'final', 'final2'. Use clear names with dates.