求教有关rand的state的问题
 

S = RAND('state') is a 35-element vector containing the current state
of the uniform generator. RAND('state',S) resets the state to S.
RAND('state',0) resets the generator to its initial state.
RAND('state',J), for integer J, resets the generator to its J-th state.
RAND('state',sum(100*clock)) resets it to a different state each time.
这一段是matlab自己对rand的state的说明，想知道state究竟是什么，具体怎么用