Final answer:
Spyware is a program that installs itself onto a computer without the user's knowledge in order to collect information about the user's activities. Adware, on the other hand, displays unwanted advertisements but does not install itself without the user's knowledge.
Step-by-step explanation:
Spyware is a program or software that installs itself onto a computer without the user's knowledge. It is designed to collect information about the user and their activities without their consent. Unlike cookies, which are small text files that websites use to track user activities, spyware is typically hidden and can monitor and gather sensitive information, such as passwords and credit card details.
Adware, on the other hand, is a type of software that displays unwanted advertisements on a user's computer. While it may be intrusive and annoying, it does not typically install itself without the user's knowledge.
Therefore, the correct answer to the question is (C) Spyware.