vi's defining characteristic, which vim inherits, is that it is _modal_. That means that it has modes, like input mode (where what you type is added to the file), and command mode (where what you type are commands to the editor).

Modal editing is fantastic: it means you don't need a meta key, or multiple modifier key combinations to do things (for which your wrists will thank you!). It frees up keybindings for different purposes, which is partly how modal editing ends up needing fewer modifier key combinations.

Best thing in editing technology yet.