Adware is software installed with the simple intent of displaying advertisements , while is/are software installed to monitor the user, taking at least partial control of his/her system without the user's knowledge or consent.

Spyware

Explanation:

Spyware is considered an unwanted software that is aimed to infiltrate or at least take partial information from your computing device and other sensitive information. It is known to be a malware type which is designed to not only gain control of a computer, but also damage it. This is often without the user's knowledge or consent.