What does it mean by select 1 from table?

Question

I have seen many queries with something as follows.

Select 1  
From table

What does this 1 mean, how will it be executed and,

Answer 1

This means that You want a value "1" as output or Most of the time used as Inner Queries because for some reason you want to calculate the outer queries based on the result of inner queries.. not all the time you use 1 but you have some specific values...

This will statically gives you output as value 1.