two trivial question of two DDK function

Hi all
    here r two DDK functions .
    RtlMoveMemory and KeDelayExecutionThread ,which is involved in my question.
    i want to know
    1st. what is the difference between RtlMoveMemory and RtlCopyMemory.
    2nd.  what is the difference between Absolute expiration times and  relative expiration times ( the last parameter passed to KeDelayExecutionThread is represented as relative expiration times , if it is a negtive LARGE_INTEGER.)

Any assistance is much appreciated and using chinese is preferable, thanks

不知查DDK文档能不能解决？

区别有：
1、RtlCopyMemory runs faster than RtlMoveMemory；
2、RtlCopyMemory源指针和目的指针不能有重叠（源块和目的块不能有交叠的块），RtlMoveMemory却可以。

绝对时间（正）是距1601年到现在的100纳秒数，相对是从当前系统时间经过100纳秒记数。