What is Update function in MS SQL SERVER

Question

Hi all last night i discussion with one of my senior he asked me one question . And that is really surprised me and really i don't ever hear about that . What is UPDATE Function in Sql server .

NOT a Update statement we are using .

Is really any function in sql server

UPDATE ()  

Answer 1

UPDATE() (Transact-SQL)

Returns a Boolean value that indicates whether an INSERT or UPDATE attempt was made on a specified column of a table or view. UPDATE() is used anywhere inside the body of a Transact-SQL INSERT or UPDATE trigger to test whether the trigger should execute certain actions.