I have a question about GarageBand track options.

hello? My name is Jeongmin Lee, a visually impaired person who is interested in computer music and loves Apple products. I have a question! If you look at the track creation options window that appears when you run GarageBand, you'll see that most of the built-in MIDI software instruments are used by default! What does guitar and bass audio mean? Originally, these computer electronic virtual instruments were intended for MIDI input! I selected Audio Guitar and Bass and created a track, and when I checked the library list, it seemed like there was a list of instruments! However, the problem is that when creating a track, I select the audio guitar and bass and press the master key, but there is no sound in that state! So I tried using the musical typing function on the computer keyboard, but there was still no sound! In other words, it looks like the MIDI input itself is not working. What does this mean for built-in software instruments and audio instruments? Does audio guitar and bass actually mean playing a real guitar, transmitting the sound from the real guitar as an audio signal, and recording pure audio using GarageBand or Logic? In other words, is it a similar principle to Adobe Audition?