The AREAS function is to return the number of areas in a reference. An area is a cell or contiguous data range.
Array is required, the reference or the data range.
Note: When there are several references in the argument, you much include extra sets of parentheses, otherwise, Excel will interpret comma as a separator.
=AREAS(A2:A3) returns 1 which is the number of area A2:A3, one area.
=AREAS((A2:A3,A5)) returns 2, which is the number of areas of A2:A3 and cell A5, there are 2 areas. Extra sets of parentheses are included.