By the end of this chapter you'll be able to…

  • 1Explain virus with one example.
  • 2Explain malware with one example.
  • 3Explain antivirus with one example.
  • 4Explain worm with one example.
  • 5Explain trojan with one example.
  • 6Explain spyware with one example.
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Why this chapter matters
Computer viruses and malware can damage files, steal information, or slow systems. Digital safety begins with recognising risk.

Before you start — revise these

A 5-minute refresher here will save you 30 minutes of confusion below.

Computer Virus - Class 7 Computer Science (CBSE)

Computer Science is not a single fixed NCERT middle-school textbook in the same way as Maths or Science. This page follows a current 2026-27 Class 7 school syllabus pattern and keeps the notes practical for students.


1. Why this chapter matters

Computer viruses and malware can damage files, steal information, or slow systems. Digital safety begins with recognising risk.

Computer answers should be precise. Use the correct term, explain it in simple words, and add one example from actual computer use.

2. Core ideas

  • virus: Learn the meaning and one classroom or daily-life example.
  • malware: Learn the meaning and one classroom or daily-life example.
  • antivirus: Learn the meaning and one classroom or daily-life example.
  • worm: Learn the meaning and one classroom or daily-life example.
  • trojan: Learn the meaning and one classroom or daily-life example.
  • spyware: Learn the meaning and one classroom or daily-life example.

3. Worked examples

Example 1: What is a computer virus?

A harmful program that can copy itself and affect files or system behaviour.

Example 2: Name two safe practices.

Use antivirus software and avoid unknown links or attachments.

4. Skill practice

  • Make a labelled diagram, table, or flow of the topic.
  • Write definitions in your own words.
  • Practise one real computer task where possible.
  • For safety chapters, write do's and don'ts.
  • For HTML/spreadsheet/database chapters, write the exact steps or syntax.

5. Common mistakes

  • Memorising terms without examples.
  • Mixing up data, information, file, folder, record, and field.
  • Writing unsafe online behaviour as a suggestion.
  • Forgetting that syntax and spelling matter in HTML and formulas.

6. Practice set

  1. Define the main idea of Computer Virus.
  2. What is a computer virus?
  3. Name two safe practices.
  4. Write two key terms from this chapter.
  5. Give one real-life use.
  6. How can you make your answer clearer?

7. Answer key

  1. Define the main idea of Computer Virus. Answer: Computer viruses and malware can damage files, steal information, or slow systems. Digital safety begins with recognising risk.

  2. What is a computer virus? Answer: A harmful program that can copy itself and affect files or system behaviour.

  3. Name two safe practices. Answer: Use antivirus software and avoid unknown links or attachments.

  4. Write two key terms from this chapter. Answer: Use terms from: virus, malware, antivirus, worm, trojan, spyware. Define each with an example.

  5. Give one real-life use. Answer: Connect the topic to school, home, online safety, data work, or webpage creation.

  6. How can you make your answer clearer? Answer: Use a diagram, labelled table, example, or step-by-step instruction.

8. Quick revision

  • Themes: virus, malware, antivirus, worm, trojan, spyware.
  • Learn definitions with examples.
  • Practise one diagram, table, formula, or syntax item.
  • For safety topics, prepare two responsible-use points.

Key formulas & results

Everything you need to memorise, in one card. Screenshot this for revision.

Definition answer
Term + meaning + example
Best for 1-2 mark answers.
Procedure answer
Step 1 -> Step 2 -> Step 3
Best for software tasks.
Safety answer
Risk + prevention + example
Best for cyber safety.
⚠️

Common mistakes & fixes

These are the exact errors that cost students marks in board exams. Read them once, save yourself the trouble.

WATCH OUT
Writing vague definitions
Add one precise example.
WATCH OUT
Skipping steps
Use numbered steps for procedures.
WATCH OUT
Ignoring safe-use rules
Mention password, privacy, antivirus, and responsible sharing where relevant.

Practice problems

Try each one yourself before tapping "Show solution". Active recall > rereading.

Q1EASY· Concept
What is a computer virus?
Show solution
A harmful program that can copy itself and affect files or system behaviour.
Q2MEDIUM· Application
Name two safe practices.
Show solution
Use antivirus software and avoid unknown links or attachments.

5-minute revision

The whole chapter, distilled. Read this the night before the exam.

  • Themes: virus, malware, antivirus, worm, trojan, spyware.
  • Use examples.
  • Write steps clearly.
  • Respect digital safety.

CBSE marks blueprint

Where the marks come from in this chapter — so you can plan your prep.

Typical chapter weightage: 5-8 marks

Question typeMarks eachTypical countWhat it tests
Definition1-22-3Terms and examples
Procedure2-31-2Steps, syntax, or table work
Application3-40-1Safety or practical task
Prep strategy
  • Learn terms
  • Practise one task
  • Make one table or diagram
  • Revise safety points

Where this shows up in the real world

This chapter isn't just an exam topic — it lives in the world around you.

virus

Useful for school computing, data work, web pages, and digital safety.

malware

Useful for school computing, data work, web pages, and digital safety.

Exam strategy

Battle-tested tips from teachers and toppers for this chapter.

  1. Use exact terms
  2. Write steps
  3. Add examples
  4. Mention safety where relevant

Going beyond the textbook

For olympiad aspirants and curious learners — topics that build on this chapter.

  • Create a mini-project using Computer Virus.
  • Make a five-question quiz for a friend.

Where else this chapter is tested

CBSE board isn't the only one — other exams test this chapter too.

Class 7 Computer Science School ExamHigh

Questions students ask

The real ones — pulled from the Q&A community and tutor sessions.

Learn definitions with examples, then practise one related task or diagram.
Verified by the tuition.in editorial team
Last reviewed on 26 May 2026. Written and reviewed by subject-matter experts — read about our process.
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