Pro is for those who needs more higher powered mac.
while air is for those who needs something more basic
To be more specific....
MacBook Air is designed to be slim, light and sleek. MacBook Air is also the quietest ultra thin laptop in the market today because it do not have any cooling fan inside.
You can do everyday tasks on it
I use it (M1 MBA) for simple video editing, photoshop
I have some friends who use the M1 / M2 MBA to do software coding and programming
In fact, you can also do some light 3D modelling works
But if you REALLY wanna go all out on heavy loaded tasks, then go for the MacBook Pro M1 Pro or Max