PUP - technical definition

(Potentially Unwanted Program) An application that is installed along with the application the user actually asked for. In most cases, the PUP is spyware, adware or some other unwanted software. However, what makes spyware or adware a PUP is the fact that it does inform the user in the license agreement before installation. Considering hardly anyone ever reads the license agreement, the distinction is a subtle one. See spyware, adware and malware.