What does this passage mean and how does it relate to Macbeth's situation?

tomorrow, and tomorrow, and tomorrow/Creeps in this petty place from day to day,/ To the last syllable of recorded time;/ And all our yesterdays have light fools/ The way to dusty death. Out of brief candle!/ Life's but a walking shadow, a poor player/ That struts and frets his hour upon stage/ And ten is heard no more. It is a tale/ Told by an idiot, full of sound and furry/ Signifying nothing.