The fold operator is z(when a paper is folded, it is shaped like the letter z).

Trigger Fold Action

In Visual Mode, use v to select the codes you want to fold, and press zf to fold them.

• zf5j will fold the next five lines
• zfip will fold an inner paragraph
• zfa{ will fold the text within {…}
• zfG will fold to the end line of a file
• zo to open a fold
• za to toggle a fold
• zR to open all folds
• zM to close all folds