Excel Array formula

An array formula performs an operation on multiple values instead of a single value. The final result of an array formula can be either one item or an array of items, depending on how the formula is constructed. To work correctly, many array formulas need to be entered with control + shift + enter. When you enter a formula this way, you’ll see the formula wrapped in curly braces {} in the formula bar.

{=SUM(LEN(B2:B11))}

References
https://exceljet.net/glossary/array-formula