TEXT turns a number or a date into text. You describe the layout you want with a pattern. Use mmmm for the month name, or 0.00 for two decimal places.
Syntax
TEXT(value, format_text)
When to use it
Getting the month name out of a date. Showing a number with a fixed number of decimal places inside a sentence. Building a label that mixes words and numbers.
What trips people up
What comes back is text, not a number, so it can no longer be added up or sorted by date. Use it for display, and keep the real value in its own column.
Set by your computer's language, not by the file. A frequent cause of a correct-looking formula being rejected.
Excel version
XLOOKUP, IFS, TEXTBEFORE and TEXTJOIN need Microsoft 365 or 2021; older versions return #NAME? instead. Choosing the older one switches every walkthrough to a formula that works there.