Applications that send information from your computer to a third party without your permission or knowledge.
Adware is any software application in which advertising banners are displayed while the program is running. The authors of these applications include additional code that delivers the ads, which can be viewed through pop-up windows or through a bar that appears on a computer screen. The justification for adware is that it helps recover programming development cost and helps to hold down the cost for the user. Adware has been criticized for occasionally including code that tracks a user's personal information and passes it on to third parties, without the user's authorization or knowledge.
Trojans or Trojan Horses are programs that appear to be innocuous even beneficial, but in fact, are harmful!. Much like the historical trojan horse, these programs appear favorable to you but in reality make your system more vulnerable to attacks and malware. The harmful contents could be anything from a virus to a remote pc or server. Trojans are designed to cause loss or theft of data, and or system destruction. Trojans can be distributed as email attachments, or bundled with other software programs.