Malware is the term given to any software which causes harm to your computer. There are many different types of malware, each of which is slightly different. Computer viruses, Trojans,
Viruses
A virus is a computer program capable of self replication. This means that once a computer is infected with a virus it can spread to lots of other files on your computer. Before the internet was common viruses spread through floppy disks. Thanks to the internet, viruses can now spread much easier than ever through file downloads.
Trojans
A Trojan is not by definition a computer virus because it cannot normally make copies of itself. Although there are some Trojans which can self replicate, these blur the boundaries slightly. A Trojan is named after the Greek Trojan horse. It simply means a seemingly useful application which opens a backdoor.
You may have no idea that you are infected with a virus, however it will open a secret backdoor into your computer which hackers can use to steal your information.
Worms
A worm is another slightly different type of malware. Like viruses they are capable of self replication but unlike viruses they are capable of sending themselves to lots of different people. These spread automatically by sending messages to people on your contact list. These are very dangerous and some of the most famous examples of malware are in fact worms.
Spyware
Spyware is similar to a Trojan but instead of allowing a hacker access to your PC, it just sits silently spying on you. Spyware can steal your credit card numbers, bank account information, and anything else that your computer knows about you.
Spyware is often bundled in with other pieces of software which means it gets installed without your knowledge.
Adware
Adware is virtually the same as spyware although it is not always a malicious program. These sit on your computer and will try to display relevant adverts to you. Many of these display so many adverts that they slow your PC down. Others will display adult content to your children which can be very troubling and upsetting.
Malware can cause harm to your computer and make it unreliable. To fight against malware and protect your computer you need a barrage of tools. These tools include virus scanners, spyware scanners, and firewalls. These utilities are available for free on certain websites and there are also complete security suites available for purchase which makes looking after your computer really easy.