There are many different threats to your computer these days. The difference is that most computers are now connected to the internet. It’s a great advantage from the perspective of gathering information, but the cost associated with that benefit is an increase in vulnerability.
Malware is a more modern term, loosely used to describe what we previously referred to as a virus. The word itself is an abbreviation for ‘malicious software’ and covers a broad range of applications that can create problems for you.
If your computer becomes infected by malware, the results will vary. Once malware is installed on your system it tends to propagate and you can pretty much bet that it will eventually bring your system to a crawl. Many malware programs will actually damage necessary operating system files. Once that happens, you will probably need someone with a fair amount of technical knowledge (and time) to get things straightened out. To prevent these attacks you can purchase anti-virus software.
Some applications will “spy” on your computer (spyware) and send information back to the author of the application. If you use your computer for banking, viewing sensitive company files, or anything else that should be kept private, spyware can be a major problem. You might not notice spyware because the person who created it is trying to get information from your system without you knowing.