Sound waves can be visualised as particles of air with alternating regions of COMPRESSION and RARIFICATION
These areas of COMPRESSION and RARIFACTION can be measured and represented electronically as the waveforms you are more used to seeing in music production software.
It’s hard to imagine all the complicated sounds we hear each day being generated only by a vibrating column of air and even harder to see how a single squiggly line can represent them accurately. This is only an introduction to recording technology so we will keep things simple for now, but be aware that even the most complicated waveforms can be broken down into component sine waves. This is a mathematical process called a FOURIER TRANSFORM.