Adware or advertisement supported software is a type of malicious software that is hidden in your computer and automatically downloads and displays unwanted advertisements whenever you perform a certain task. It can spoil your computer's memory and hinder many vital system processes. In many scenarios, they are a threat to any confidential data stored in your computer. Though considered mild, adwares can be highly disruptive in times when they popup unsolicited advertisements. Moreover, sometimes, they even display advertisements that are not meant for children.
Adwares are seen as a way to recover development costs by the programmer, and in certain cases it may even allow the software to be offered to the user free of cost or at a reduced price. However there are many dangerous threats associated with adwares. If you are using Internet without any proper anti-adware software, there is a high possibility that your system will get infected by adwares.
Adwares can be highly dangerous as they can transmit confidential and private. In most cases, adwares send vital information about your browsing habits. If you have been infected by adwares, you are highly vulnerable to other threats like identity theft.
If you want to be protected against adwares, you must get a good anti-adware program. Many software packages have been developed to find, quarantine, and delete adware. The most popular anti-adware applications are Ad-Aware (which can be downloaded at http://www.lavasoftusa.com/products/ad_aware_free.
php) and Spybot - Search & Destroy (http://www.safer-networking.org/en/download/index.
html). These programs are free and are designed specifically for spyware detection.
John Cicero has written articles on topics such as AdWare, Malware and Spyware for The Tech FAQ.