By GarageBand application's Resource folder., Fair use,
Garage Band
To learn more about music theory and audio production (for useful things in High School like podcasts), we had a few Technology Integration classes on Garage Band
example of a production on the app
Types of Instruments
Piano/ Keyboard
These two images below show some examples of more "complex" Keyboards, that allow you to make many different sounds, unlike the one on the top, that is just the basic sound and form of a normal and classic Grand Piano.
Sound Library
Apple provides GarageBand users the option to download some already made songs and beats, so they can learn and explore the compositions of it
Microphone
The "Studio Narrator" option on the top left is made mainly to record and change your voice in more of a professional way, unlike the "Fun" tab represented in the top right. This option allows you to change your voice to things like a chipmunk, a robot etc, which would be considered a fun way of recording yourself or other people.
Bass
The string instruments contain an option to play singular strings (bottom right picture), or actual chords ( left picture). The feature to use the already made up chords is super useful, because helps beginners that don't have any experience with music theory to create and learn something new.
Guitar
Guitar representation with chords included
Standard guitar representation
Standard Drums
Drummer
The drummer option on the app allows you to choose between various "people" with different playing styles, so you won't have to learn how to manage the instrument, and they will play something of that specific style you chose.
AMP
The amp is used to plug an instrument and transfer the sound from it to the device. This helps someone that already plays something to edit or use that sound on a project, song etc.