nvim:tldr:1c1a8

The command u is a command in Vim, a text editor. It is used to undo the last operation or changes made in normal mode.

Here is how it works:

1. Press the Esc key to ensure you are in the normal mode. This is the mode in which you can navigate and perform various commands in Vim.
2. Then, press the u key immediately after the Esc key.
3. The u command will undo the last operation you performed. It could be a deletion, insertion, or any other change made to the text.
4. If you repeatedly press u, Vim will continue to undo previous operations until there are no more to undo, or until you reach the limit of undo history set in your Vim configuration.

In summary, the u command is used to quickly undo the most recent change made in Vim normal mode.