2=2 evaluates to TRUE, so it has no effect on the query.
Usually people do that when they want to construct a query programmatically.
If you start with 1=1 or 2=2, then all the additional clauses that you may want to add can be prefixed with an AND. For example:
SELECT
col1,col2
FROM
SomeTable
WHERE
1 = 1
AND StateCode = 'CT' --- dynamically added sections
AND ZipCode = '06901'