What does “select count(1) from table_name” on any database tables mean?

Question

When we execute select count(*) from table_name it returns the number of rows.

What does count(1) do? What does 1 signify here

Answer 1

Difference between count(*) and count(1) in oracle?

count(*) means it will count all records i.e each and every cell BUT

count(1) means it will add one pseudo column with value 1 and returns count of all records