Excel has three simple counting functions, and they answer three different questions. Picking the wrong one is a classic reason for a report total being off.
COUNT: numbers only
=COUNT(A2:A100) counts cells that contain numbers (dates count too, because dates are numbers). Text is ignored.
COUNTA: anything not empty
=COUNTA(A2:A100) counts every cell with something in it: text, numbers, errors. Use this to count how many names you have.
COUNTBLANK: empty cells
=COUNTBLANK(A2:A100) counts empty cells. It also counts cells that contain a formula returning "" (empty text).
Quick comparison
Imagine five cells: 10, "Amit", empty, 25, "". COUNT gives 2. COUNTA gives 4, because the empty text from a formula counts as filled. COUNTBLANK gives 2.
Add a condition
To count with a rule, use COUNTIF or COUNTIFS. For example, how many rows have a name but no phone number: =COUNTIFS(A2:A100,"<>",B2:B100,"")
Completeness check for reports
Before sending a report, compare =COUNTA(A2:A500) with =COUNTA(B2:B500). If the numbers differ, some rows are missing a value.