Computer Science (EM) 2020 — Class 9 Punjab Board book

Is kitab ke baare mein

This is the official Punjab Curriculum and Textbook Board 'Computer Science & IT 9' for the 2020 curriculum (English medium), authored by Dr. Muhammad Atif Chattha and edited by Amjad Riaz. It is a complete rethink of the subject compared to the old computer-studies books: Unit 1 starts with problem-solving methodology — problem-solving steps, flowcharts, algorithms, test data, and verification vs validation — before any code or hardware appears. Unit 2 (Binary System) then builds the number-system foundations: decimal, binary and hexadecimal conversions, memory and data storage, and a full treatment of Boolean algebra with truth tables and laws.

The second half of the book is what makes this edition stand out. Unit 3 (Networks) covers computer networks, topologies, TCP/IP protocols, IP addressing and routing in plain language. Unit 4 (Data and Privacy) is a genuinely modern chapter: ethical issues in data security, the Caesar and Vigenere ciphers with worked examples, cryptographic keys and passwords, phishing, and denial-of-service attacks. Unit 5 (Designing Website) closes the book with hands-on HTML — tags, text formatting, lists, images, hyperlinks and tables — so students build real webpages. Every unit ends with a summary and exercise, and the book closes with answers, a glossary and an index.