What use do these round pads have on PCB?
Probably they connect to a "bed of nails" test equipment.

TP1, TP2 and two other circular pads (that appear to be referenced TP_something) are "test points" and if this circuit board is a medium to high volume then it's likely that the test points make contact with test equipment during manufacture to inject (or measure) certain voltages in order to determine that the correct components have been fitted.





The two thru-hole plated pads might be fixing a 0.1" 2 pin connector with the square pad being normally regarded as pin 1 (a polarity guide).