We all have heard the terms Virus,Worms, trojans and spyware but only a few of us know the difference between them.We generally consider everything that is detected by an antivirus as virus but this is not the case.The antivirus not only provides protection against viruses but it also protects us from trojans, worms and spywares.All these can be harmful to your computer hardware and software.Today I will differentiate all these terms from each other .Ok lets start from the introduction of viruses
VIRUS: A virus is a self replicating program that attaches itself to an executable file.When the file is executed the virus automatically gets executed and enters into system memory .Once it enters into system memory it either searches for other files that can be infected or stays in the background and infect the files that are uses the virus infected program.
WORMS: Worms are very similar to viruses but differ in way that they do not bind themselves to executable files instead to replicate themselves they uses the network.If you find excessive use of your network bandwidth then you may be infected by a worm.So,a worm do not require a user to execute any file for its execution it can work without user intervention.
TROJAN HORSE: A trojan horse is harmful program which may seem harmless to the user before its installation but instead it is programmed or reverse engineered to facilitate unauthorised remote access to the computer.Trojan’s do not replicate themselves.
BACKDOOR: A program that allows a remote user to execute commands and tasks on your computer without your permission. These types of programs are typically used to launch attacks on other computers, distribute copyrighted software or media, or hack other computers.