Spyware - Definition from the Hotspot Shield Glossary
Spyware is one of the original forms of monitoring programs and is used to record information from your computer about your actions and behavior. The actual term “Spyware” is quite generic and does not refer to one single program, instead it refers to any program that fits the purpose.
Spyware may seem like a normal program, but behind the scenes it will have additional functions that will allow it to gather information from your computer when the program is active. Not all Spyware is malicious and some may be used for advertising purposes, but in most cases the information gathered will be sensitive such as passwords, credit cards details and email account logins.