In a text editor or terminal, command mode is a mode of operation where the user can execute various commands and keyboard shortcuts to manipulate text or perform tasks. This mode is different from insert mode, where the user can enter or edit text. In command mode, the user can move the cursor around the document using various navigation keys or execute commands that manipulate or search for text, such as deleting a line, searching for a word, or copying and pasting lines of text. Command mode is an essential feature of many text editors, including Vim and Emacs, as it allows users to edit text more efficiently and effectively.