Meaning of two items in Repetier Host (2 replies)

Hi,
In Repetier Host in the manual control tab, there are two items under the control buttons for the axis'. One is feed rate and has a slider for adjustment and the other is flow rate and also has a slider for adjustment. What is feed rate? What is flow rate? It might help me to understand these so I know what they do and can make the appropriate adjustments.

Thanks Vance