A thread is a sequence of messages or posts on a specific topic within an online platform, such as a forum or social media. Threads allow users to engage in discussions, share information, and ask questions, creating a structured conversation around a particular subject. Each thread typically starts with an initial post, followed by responses from other users. In computer science, a thread refers to the smallest unit of processing that can be scheduled by an operating system. Threads enable multiple tasks to run concurrently within a program, improving efficiency and performance. They are essential for applications that require multitasking, such as web browsers and video games.