Primary Modes

Helix is a modal editor, and has two primary "modes" of operation.

Normal mode, which is the mode you start in by default, and which
you will likely spend a substantial amount of time in, is the main
mode used for text editing operations.

Insert mode, which can be entered in numerous ways — such as by
pressing i — is used for typing text.

A third mode, called "Select" or "Extend" mode, is essentially a
subset of Normal mode, where moving cursors leaves selection
anchors in place — useful for making modifications to existing
selections. Select mode can be toggled by pressing v.

You can see which of these three modes you are currently in by
looking at the left side of the statusline. It will display:
  NOR — Normal mode
  INS — Insert mode
  SEL — Select mode