So a Trojan is not completely a virus but a malicious software downloaded from the internet. A trojan has just one mission and that to steal your computer files or gain admin access to a server or computer.
The main difference between a virus and a trojan is that a virus is meant to corrupt files and multiply while a trojan has only one task to do and it won’t do anything else only that which it was meant to do.
A trojan could be transferred to your computer by simply just downloading the wrong file from the internet. Other ways in which you could get a trojan are;
* Clicking an unknown email link
* sharing Bittorrent files
* clicking on ads
Just as for virus, the best way to protect yourself against Trojans is to get yourself a very powerful antivirus software. And also try not to click on every ad you see online and always check an email to know who it from before opening.
Even though we do all these it is still not 100% assured that we’re protected because we could always make a mistake, so that why it also advisable to have a backup of all your files, you could back them all up to the cloud and get access to them anytime you want.