.a is an archive of code: compiled but not linked. You would link statically with it during your program's final link step.
(.a 是编译了但尚未链接的 obj 文件的 集合体。静态链接可用它。)
.lib can be either the same as .a, or a magical so-called "import library": a thin placeholder which causes you to require a .dll at runtime.
(.lib 可以就是 .a, 也可以是 所谓的 输入库,当使用 动态链接时,要用它, 动态链接得到的exe程序,运行时 还要用到 .dll ) .
.a结尾是linux静态库文件
.lib结尾应该是windows静态库文件吧