[CREDO]

Basically spyware is a marketing tool, it gathers information on where you go on the net and what you do there and sends it to a site where it can then be sold as "market research"

Allot of schools in America cut deals with companies to supply computers to them at a cheaper rate with spyware installed to track a certain demographic of consumers, namely school age children.

So overall you have unnecessary programs running taking up your CPU's resources and your bandwidth when sending info across the net without you knowing its going on at all.

Adware is a whole different beast. Adware usually starts off the same as spyware as in it gathers info on where you go and what you do, but it can then position ads relevant to you when you visit certain sites. this can be done with either a program running or even a tracking cookie (cookie: a file written to your temp internet folder)

Spyware and adware are fast becoming on of the most annoying things on the internet today, its use is getting massively widespread and its getting harder and harder for companies like lavasoft and other makers of spyware removal tools to keep up. particularly with the latest trend of spyware that keep writing the executable file from a undetectable source over and over with random filenames whenever its removed. www.lop.com is a main offender of this. you keep scanning and it just keeps coming back.