A formula that performs calculations on multiple values at once instead of a single cell.
Try it with AIAn array formula works on a whole range as a unit — e.g. multiplying two columns and summing the result in one step. Legacy versions need Ctrl+Shift+Enter; modern Excel handles arrays natively via dynamic arrays.
=SUM(A2:A10*B2:B10)In legacy Excel it commits a formula as an array (CSE) formula. Microsoft 365 no longer requires it.