The term "um" is a common filler word used in spoken language. It often indicates hesitation or uncertainty while a speaker thinks about what to say next. People use "um" to fill pauses in conversation, allowing them time to gather their thoughts without losing the listener's attention. In linguistics, "um" is classified as a discourse marker. It serves various functions, such as signaling that the speaker is not finished talking or that they are considering their next words. Similar filler words include uh, like, and you know, which also help manage the flow of conversation.