Thread Pools and Executors

Know the Vocabulary

This lesson uses the terms below many times. Read them once now, and come back here when a later section needs one.

• Task: One small piece of work that a program wants done, such as sending one email. People also call it a job.
• Thread pool: A limited group of threads that stay alive and run many tasks, one after another.
• Worker thread: One of the threads in a pool, which takes a task, runs it, and then takes the next one.
• Task queue: The waiting line inside a pool, where tasks wait until a worker is free.