A Pre Amp, or a "Mic pre", is a tiny amplifier that goes before your actual amplifier. This has to do with Line Level vs Mic Level. A microphone, or the cable coming straight from a guitar, typically outputs a much quieter signal than your interface, or recording device, is expecting to "hear". If you simply crank the gain knob up to 11, you're going to hear fuzz. Some people confuse this as real noise in the room, but it's actually the gain device itself. This is referred to as Self-Noise.
Anything that has a gain knob, technically has a pre-amp installed. The concern isn't whether or not you have a pre-amp. The concern is how clean or "low-noise" your pre-amp will operate.
Try it yourself. Simply unplug any inputs and crank the gain. What do you hear?
The solution is a quality Pre Amp. Pre Amps offer "clean gain". All loud, with no fuzz. That's why they can often be a bit pricy.
Most commonly used are the Cloudlifter and the Fethead. Both use a 3-pin XLR cable. The Cloudlifter (left) states it will add "up to 25dB of clean gain" to your input. The Fethead (center) states "up to 27dB of clean gain". Both of these use Phantom Power