1. Rootkit :
Rootkit is a set of application, a type of
malware that is designed to infect a target PC and allow an attacker to install a set of tools that grant him persistent remote access to the computer. The malware typically pretended itself as normal files that “hide in plain sight” so your antivirus software overlooks them. It enables administrator-level access to a computer or computer network. The motive is to steal the identity information from your computer, often to gain control of a system. It is difficult to detect and remove, requires the specialized tools to remove.
2. Spyware :
Spyware is a kind of malware that perform certain works include watching and tracking of user actions and collecting personal data. Spyware programs generally install themselves on system and provides profit to the third party by collecting data of system user without his consent. Malicious spyware also try to catch passwords and personal information of the users by running in background in the system.
Difference between Rootkit and Spyware :