What is the difference between null and not null

Question

will you plz any explain these in sql

Answer 1

NULL means that database columns can hold NULL values . NOT NULL means a column to NOT accept NULL values.

Answer 2

Null in other way means zero or empty value.
Thus, Null means you can leave that field empty.
And Not Null means you can't leave the value of that field empty.
E. g when you fill a form online, there is an asterisk(*) shown near Name field, password, etc., so that field is not null, those values are important and should be filled.

Answer 3

i can understand Will you plz give me any examole for these

Answer 4

Okay tq bro