Recording with 2 separate mics?

I’m having trouble understanding the stereo function . My understanding is that i can’t record on 2 separate mics at the same time. If so, then what is the stereo selection for?
If I use a mixer, could I record in stereo?
Thank you

Yes, a stereo USB mixer, or an analog mixer if you have a regular soundcard with stereo line-in (color coded-blue).

Or, a stereo audio interface.

Note that mixers & audio interfaces work with stage/studio mics (balanced XLR connections). They are not compatible with “computer mics”.

Or there are a few stereo USB mics, such as the Blue Yeti.

People digitize stereo analog tape or viny records using a soundcard or USB audio interface. Or there are lots of USB turntables and USB cassette players.

Mono to stereo leads/adaptors lets you record 2 inputs… 1 mic on left and 1 mic on right of PCaudio line in jack socket etc
OR … RCA to stereo leads/adaptors to stereo jack

or build a cheap homemade splitter… a few resistors and 3 jack sockets