adware

Internet Explorer's capability to download and run ActiveX controls is a double-edged sword. When used properly, ActiveX controls greatly expand the power of Internet Explorer. Unfortunately, the developers of spyware, adware, and other forms of unwanted software figured out long ago that ActiveX is a great way to sneak unwanted programs onto an unsuspecting user's computer.

These are most commonly heard terms in the network security but few know what exactly are they. All three appear to be quite same but there is a difference between them.