What are Malware , Worms and Trojan horses in Computer

MALWARE

Malware is short Malicious software. The word refers any program that infiltrates and harms a computer without the user's consent. Malware is a general term that includes computer viruses, worms, Trojan horses , spyware, and spam. Malware can slow down computers and networks; it can be annoying, or actively destructive. 

WORMS

A computer worm is a program capable of reproducing and spreading itself to another computer system, usually means of a computer network. Worms spread out any human action, and thus differ from virus. Viruses spread only when the user does something, such as runny an infected program or attaching an infected file. A worm emails copies of itself to other computers, infects them, and then uses the address book, of the infected computer to spread further.

Trojan Horses

A Trojan horse is a program that appears useful, but is actually programmed to pass the user's data to someone else.Trojan horses attempt to steal and pass on confidential information such as passwords and credit card numbers. They do not reproduce by infecting other files or by self-replicating like viruses and worms. A Trojan horse enters a computer system because a user installs it, useful and harmless program.