Non-inverting gain
Feedback is the amplifier’s measuring stick. Increasing Rf relative to Rg asks it to make the output bigger.
A = 1 + Rf / Rg
Ideal non-inverting amplifier with Rg to ground. Gain does not guarantee output swing or bandwidth. Check supply rails, input common-mode range, gain-bandwidth, slew rate, stability and resistor noise in the chosen op-amp datasheet.