What is a CLAUSE in terms of SQL?

A clause in SQL refers to the part of a SQL statement that can be used to filter or manipulate data in different ways. There are several types of clauses in SQL, including:

1. WHERE: This clause is used to filter the records that are returned from a SELECT statement. For example, you might use a WHERE clause to only return records where a certain condition is true.

2. FROM: This clause is used to specify the table that you want to select or delete data from.

3. GROUP BY: This clause is used with aggregate functions (like SUM, AVG, etc.) to group the result-set by one or more columns.

4. HAVING: This clause was added to SQL because the WHERE keyword could not be used with aggregate functions. It is used to filter the results of a GROUP BY clause.

5. ORDER BY: This clause is used to sort the result-set in ascending or descending order.

Each of these clauses plays a crucial role in defining the parameters and constraints for a SQL query.