请示 (qǐng shì) means 'to ask for instructions from a superior' — it implies a hierarchical relationship where you seek approval or a directive before acting. Unlike 请教 (qǐng jiào), which asks for advice or knowledge from someone more experienced, 请示 is about getting permission or orders. 指示 (zhǐ shì) is the noun or verb for the instruction itself, not the act of requesting it.