Adware in the purest sense of the word is not a dangerous thing, designed only to display targeted advertising to you while browsing the internet. It was originally developed by marketers to be non intrusive and use very little system resources. You can easily recognize adware by the display of pop up advertisements on your computer screen, often appearing when you perform searches or land on different websites.

Adware can be very annoying, and in the past few years much of adwares functional characteristics have begun to resemble spyware. A large percentage of adware today includes code that tells the advertiser something about you. It often relays information about which sites you visit on the internet, how much time you spend on each site, and what type of content you viewed. Although marketing people consider this information to be harmless to you, most users consider this type of data gathering to be an invasion of privacy. Adware that is delivered in the form of email often tells marketers when you opened the mail, how long you looked at it, and what you did with it.

Spyware is similar to adware, but much more dangerous. Instead of transmitting information about your web behavior to marketers, spyware is designed to steal confidential information such as account numbers, names, addresses, etc As adware continues to evolve into a more sophisticated marketing tool, much of it is now capable of gathering non-marketing information that is more sensitive in nature. This new type of hybrid adware is sometimes referred to as adware-spyware.

Adware is normally included in downloaded software known as freeware. In exchange for using free software, you agree to the installation of adware. Most free software includes a statement about the included adware in a license agreement that usually goes unread. Other adware comes in the form of email, with code hidden in embedded graphics or even in the HTML code. If you forward an adware email to someone, they can get it too. Like spyware, adware installs very quickly, often without the users knowledge. Adware is not a virus, so antivirus software will never detect it.

If your computer is suddenly running very slowly, is plagued with pop-up ads, or if your browser home page has changed, chances are you have adware on your computer. If you have adware you probably have spyware too, as they both tend to go hand in hand.

Adware and spyware can sometimes be difficult to remove, and its best to use adware removal software. Because the two are so closely related, most good spyware removers will find and kill adware too. Since new adware and spyware is introduced into the internet every day, you may have to try several adware removers before you find one that will detect and destroy all the adware on your computer. Many free adware removers are available, but its best to get a paid version of this software that will protect you from future problems.

Due to the danger and prevalence of adware and spyware on the internet today, it is now considered a standard practice to use anti-spyware/anti-adware software. For the best anti-adware software, consider McAfee AntiSpyware, Spyware Doctor, Sunbelt Counter Spy, Adaware, Webroot Spy Sweeper, or eTrust Pest Patrol.