summary: What does 1st Qu. & 3rd Qu. mean?

Hi All

I have a time series dataset which produnes the following stats from the summary function

Min 1st Qu Median Mean 3rd Qu Max
51690 57530 97330 112500 167300 216700

What does the 1st Qu. & 3rd Qu. mean? I cannot find where this is explained anywhere.

Any help on this would be very much appreciated