Simplifying if you know or have little experience with spanning tree, the implementing rstp is an easy task.
first there are 5 states in spanning tree:
each state has its own time unitl it changes to the other time, so in the Rstp implementation the first three states resume into only one state called discarding, so there are only three states:
THE ADVANTAGE WITH RSTP IS LESS CONVERGE TIME OR LESS TIME FOR THE PORT TO CHANGE FROM BLOCKING TO FORWARDING.
ANOTHER FEATURE IS THAT THE SWITCH THAT SUFFERS THE CHANGE OR INESTABILITY INMEDIATELY FORWARDS THE NEW INFO BPDUS TO ALL THE SWITCHES, INSTEAD OF THE OLD STP THAT IT MUST INFORM THE ROOT SWITCH AND THEN THE ROOT SWITCH INFORMS ALL THE SWITCHES ABOUT THE NEW LAYER 2 TOPOLOGY.