what is the use of threadpool in muduo/base?

[jackwsl]

i note that in folder muduo/base, there are two classes : Thread( in file thread.h) and ThreadPool( in file ThreadPool.h)， i also note that in folder muduo/net, there are two classes : EventLoopThread( in file EventLoopThread.h) and EventLoopThreadPool( in file EventLoopThreadPool.h)

After i see muduo frame , i think EventLoopThread and EventLoopThreadPoll are used in multiThread TcpServer model . but what is the use of ThreadPool and Thread in folder muduo/base , i don't know what do they do ... can you tell me which module use class Thread and ThreadPool ......

thanks