What is a Spyware?

Spyware is computer software that collects personal information about users without their informed consent. The term, coined in 1995 but not widely used for another five years, is often used interchangeably with adware and malware (software designed to infiltrate and damage a computer respectively).

Personal information is secretly recorded with a variety of techniques, including logging keystrokes, recording Internet web browsing history, and scanning documents on the computer's hard disk. Purposes range from overtly criminal (theft of passwords and financial details) to the merely annoying (recording Internet search history for targeted advertising, while consuming computer resources). Spyware may collect different types of information. Some variants attempt to track the websites a user visits and then send this information to an advertising agency. More malicious variants attempt to intercept passwords or credit card numbers as a user enters them into a web form or other applications.

What is a Adware?

Adware or advertising-supported software is any software package which automatically plays, displays, or downloads advertising material to a computer after the software is installed on it or while the application is being used.

It is software integrated into or bundled with a program. It is usually seen by the programmer as a way to recover programming development costs, and in some cases it may allow the program to be provided to the user free of charge or at a reduced price. The advertising income may allow or motivate the programmer to continue to write, maintain and upgrade the software product.

Some adware is also shareware, and so the word may be used as term of distinction to differentiate between types of shareware software. What differentiates adware from other shareware is that it is primarily advertising-supported. Users may also be given the option to pay for a "registered" or "licensed" copy to do away with the advertisements.