Which modes in which he speaks? Never heard of this.
Grab a copy of "vi" and you'll get a taste of modes.
vi has two modes:
- command mode
- insert mode
In command mode, the letters of the keyboard perform editing functions (like moving the cursor, deleting text, etc.). To enter command mode, press the escape key.
In insert mode, the letters you type form words and sentences. Unlike many word processors, vi starts up in command mode.
Old WordPerfect was similar.