In PHP if we are working on database and it is required to limit the data we want from the select query we can do it by appending a clause in the query. This can be helpful in pagination etc in our page.
Lets take an example in which we are required to fetch only 40 records:
$sql = "SELECT * FROM EMP LIMIT 40";
The above sql query when gets executed it will give only 40 records as a result. The large number of data sometimes lowers the performance so there limiting the data improves the performance.