Introduced in Delphi 2006, code folding lets you collapse or expand regions or blocks of code. Collapsing your code creates a hierarchical view of the code and makes it easier to read and navigate. The collapsed code is not deleted, but hidden from view in Code Editor until you expand it.
Delphi generates code that contains code folding regions, but you can add your own collapsible regions as needed.
Are you using code folding? I do, every day. If you do also, what do you fold: