区别不是很大,硬要说区别的话,post的表达更中立,而position有隐晦的表达水平、阶级的不同.举个亲身经历：
我有一次在group project的进程报告里（progress report）写了：my postion in the group is.
老师改的时候吧position改成了post.
理由是：post more strongly connotes an assigned station,especially a specific geographic place.Position on the other hand more strongly connotes a rank or class.