Which term describes unwanted software that displays advertisements?

The term that specifically describes unwanted software designed to display advertisements is adware. Adware creates advertisements that may interrupt user activities and can lead to a cluttered browsing experience. It generates revenue for its developers by presenting ads to users without their consent—often in a way that is intrusive.

While other terms are related to unwanted software, they refer to different types of threats. Spyware is designed to gather personal information without the user's knowledge, while malware is a broader category that includes various malicious software types, including viruses, worms, and adware. Ransomware, on the other hand, locks users out of their devices or files until a ransom is paid, serving a very different purpose than that of adware. Therefore, adware is the most accurate term for software that primarily focuses on generating advertisements.