What is a trojan?

I was downloading music files, and my antivirus popped up telling me it had found and deleted a trojan.im on symantic antivirus, and its really good, bt im scared. what is a trojan and what does it do? why is it different from a virus, and how does it get into your pc?

What is a trojan?network

Heh, can we copy paste more?

If you don't want to read all that it's just a piece of malware that can be disguised as something else. For instance, you download a picture, the icon looks like a picture, you open the picture and you see a pretty face or whatever, you close it and think all is fine. Next thing you know your computer is shutting off randomly or what not.. so you right click on that picture and go to properties (assuming you can't see the file extension) and you notice it as a .exe (indicating its a program), that's your trojan. It can be powerful enough to give the 'master' total control over it's new 'slave' computer... fun stuff...

Additional info, it's likely to send your IP everytime you login to your internet to the master so he/she can have fun with you until you remove it...

What is a trojan?norton

A destructive program that masquerades as a benign application. Unlike viruses, Trojan horses do not replicate themselves but they can be just as destructive. One of the most insidious types of Trojan horse is a program that claims to rid your computer of viruses but instead introduces viruses onto your computer.
Trojan is a form of virus that harms even the user (YOU). This virus could be transfered to your body if you are in contact with ur pc even for just some minutes. The symtpms include headache, vomitting and emmiting some blood when urination. The worst is that it could be transmitted into others and would cause psychological problems and would lead to death. If you have theses symtoms, you better consult a doctor...Some of them recommend to take upsome antivirus pills...these pills can be purchase from norton, avg, trendmicro and many others....
it's just another type of virus: it hitches on a programme and installs intself into your computer when you install the programme