Any built-in can be used as an expression. The syntax for a function call is the name of a function followed by its argument list in parentheses.
function ( [expression [, expression...]] )
Any built-in function.
Any expression(s) matching the data type and parameter count expected by the function.
abs (variable) select avg (qtysold + 3) from sales; select dateadd (day,30,caldate) as plus30days from date;