网上找到的回答，记录一下
1、The Thread class is used for creating and manipulating a thread in Windows. A Task represents some asynchronous operation and is part of the Task Parallel Library, a set of APIs for running tasks asynchronously and in parallel.
2、The task can return a result. There is no direct mechanism to return the result from a thread.
Task supports cancellation through the use of cancellation tokens. But Thread doesn't.
3、A task can have multiple processes happening at the same time. Threads can only have one task running at a time.
4、We can easily implement Asynchronous using ’async’ and ‘await’ keywords.
5、A new Thread()is not dealing with Thread pool thread, whereas Task does use thread pool thread.
6、A Task is a higher level concept than Thread.
