What does the number in brackets mean for type int?

Question

SQL

I looked at the fields of the table with a query , in the Type column there are entries int (18) and bigint (20). What does the number in brackets mean here? I am attaching a picture:SHOW COLUMNS FROM b_file

Answer 1

to this width in characters, the value will be left-padded with zeros when displayed in the console, provided the field has the zerofill attribute set.
those. 100 for int(18) will be displayed as 000000000000000100