More correctly, it changes the values to the format the is defined in each selected cell. If cells are formatted as text then their contents will be changed to text. If cells are formatted as general (or various number formats) text numbers in those cells will be changed to numbers.
I entered numbers proceeded by a single quote in a column then formatted each cell with a different format. When I used Alt DEF the numbers all changed to the formats of their cells.
Alt DE brings up the text to columns wizard and F finishes it with the default settings (delimited with whatever delimiters were last used).
Note that ALT+D+E brings up Text to Columns. And the F just selects the Finish button on Text to Columns.
All these years, I have been doing Text to Columns manually, and I was never aware of this shortcut!
(Though it isn't really that much more, just different:
- Click Data menu
- Click Text to Columns
- Click Finish