Feed rate is the linear advance of the cut — the table speed in milling, the plunge in drilling, the carriage travel in turning — expressed in inches or millimetres per minute. It is a derived number, not a chosen one: for milling, f_m = RPM × f_z × z, the spindle speed times the chip load per tooth times the number of flutes; for drilling and turning, f_m = RPM × f, with f the feed per revolution. In the worked case of a 1-inch, 4-flute end mill at 100 sfm, the 382 rpm spindle speed and 0.002 in/tooth chip load combine to a 3.1 in/min table feed.
The distinction worth keeping straight is that cutting speed and feed rate answer different questions: surface speed governs how fast the edge slides over the material, while feed governs how much material each pass of an edge removes. Change flute count and the feed changes with it at the same chip load; change diameter and the RPM changes at the same surface speed, dragging feed along. Adding depth and width of cut on top of the feed gives the material removal rate — the number that ties the cut to the machine’s spindle power.