Spyware is basically a computer code that was written to take control of an unsuspecting victim's computer.

"Take control" does not necessarily mean your mouse pointer starts flying around your computer screen and clicks on any icon at random. The bare nature of spyware is that it operates without the user's knowledge. Some of the functions of spyware can range from the less harmful such as monitoring of your web surfing habits to the extremely harmful like logging keystrokes or remotely controlling your computer.

Spyware can log information such as what sites you often visit or what terms you usually enter in search engines. It then transmits your usage patterns to the author or some central program, which in turn sends pop-up screens or diverts your browser to a site which has a theme that is based on the data that they have gathered. So if a user of a spyware-infected computer likes to visit sites about dogs or pets, that user may suddenly find annoying pop-up ads about dogs or pets.

These types of spyware are also known as adware. They are a nuisance especially when browsing and their activities undoubtedly raise privacy concerns.

The more harmful aspect could include stealing personal information from websites that you do online transactions with, or even recording your keystrokes when entering passwords in banking or credit card transactions. The data that are harvested by the spyware are sent over the internet to the author of the spyware and the net result is identity theft. These kinds of spyware behave in a similar fashion as trojans.

Spyware infiltrates your computer mostly by browsing and by visiting the "darker" side of the internet. Here are some common sources of spyware:

• pornography sites;
• download sites for illegal software and/or media such as movies, music and the like;
• peer-to-peer (P2P) networks;
• some innocent looking and informative sites but have maliciously written scripts (usually in the form of javascript) which can exploit unpatched browsers;
• installing some freeware or shareware programs which come bundled with spyware and adware;

There are two constants on how spyware works:

1. they operate without the computer users' knowledge;
2. spyware always sends its data through the internet.

Because a spyware has to run in the background, the user will very likely notice a slowing down in their computer's performance. With data being constantly harvested and sent via the internet, the internet browsing speed will very likely slow down too. If you notice that your computer is showing these two symptoms, there is a big probability that your computer is infected.

Most reputable antivirus programs these days come in a "protection suite" package. This means aside from the antivirus program itself, you also get an antispyware, antispam and firewall in the package. Each of these programs help in adding layers of defense in your computer. In our own experience, Kaspersky Antivirus and its companion suite is probably the most complete and most efficient at protecting against practically all forms of computer threats.

Be aware though that an antivirus program alone will not detect and eliminate spyware. For this purpose, you will need to get a hold of "antispyware" or "spyware removal" software. Most of these suites that we just mentioned will have one packaged in them. There are also standalone programs whose functions are basically to detect and eliminate spyware and even offer real-time protection from further spyware intrusion.

There are many different programs to choose from, some are free while others are retail. Each program has its own strengths and weaknesses. You can find a very comprehensive review of antispyware products at C-Net. Doing a search for reviews and comparisons through your favorite search engine will certainly provide enough results in order for you to make a sound judgment as to which software is right for you.

An area of concern that casual computers should know about is that there are a lot programs out there now that are actually rogue anti spyware programs.

They come with very catchy names and promise to rid your computer of spyware but in reality they are installing more. Differentiating a credible antispyware program from a fake can be difficult especially for beginners. Here is a site that is a pretty good starting point for beginners to learn how to detect a fake.