How do square brackets differ from parentheses in T-SQL Server queries?

In T-SQL Server queries, square brackets [] and parentheses () serve different purposes:

Square Brackets []
– Used to enclose identifiers, such as table names, column names, and database names.
– Allow the use of reserved words and special characters in identifiers.
– Prevent errors caused by identifiers containing spaces, punctuation, or special characters.

Parentheses ()
– Used to group expressions, define the order of operations, and clarify complex queries.
– Employed in functions, such as aggregate functions (Example; SUM (), AVG ()) and string functions (Example; Subtracting (), Replace ()).
– Used to define subqueries and derived tables.

In this example, square brackets [] enclose identifiers, while parentheses () group expressions and define the order of operations.