白话理解吧：

线程:操作系统的最小单位，是一串指令的集合。

进程：各种线程的集合，封装到一起，干事业！

进程与线程的区别？

1. Threads share the address space of the process that created it; processes have their own address space.
2. Threads have direct access to the data segment of its process; processes have their own copy of the data segment of the parent process.
3. Threads can directly communicate with other threads of its process; processes must use interprocess communication to communicate with sibling processes.
4. New threads are easily created; new processes require duplication of the parent process.
5. Threads can exercise considerable control over threads of the same process; processes can only exercise control over child processes.
6. Changes to the main thread (cancellation, priority change, etc.) may affect the behavior of the other threads of the process; changes to the parent process does not affect child processes.

翻译下：

　　线程是执行的指令集

　　主线程的修改会影响其他线程

　　线程与线程之间没有实际的立足关系

就这些，用起来理解就行。