Does anyone has clues on mysqli_num_rows function in PHP?

Question

when user getting login, the function (mysqli_num_rows) is used, I don't know about the correct usage, does any one has clues on it.

Appreciated in Advance

Answer 1

mysqli_num_row function returns the number of rows affected by the current query.
If the count is at least one it means that the record exists for the query.
So we cam assure that the user has registered using that email or id and password.