Question

how do viruses and worms affect computer

Answer 1

Explanation:

An important distinction between computer viruses and worms is that viruses require an active host program or an already-infected and active operating system in order for viruses to run, cause damage and infect other executable files or documents, while worms are stand-alone malicious programs that can self-replicate

Answer 2

Actually virus and malware are a man made virus which makes our computer work slow and get affected with viruses
Human built it secretly in any application