Suppose, sometimes you just need entry in the table with all the default values.
For example you have a Student table which looks like as below
CREATE TABLE #tmpStudent (StudentId INT IDENTITY(1,1),
FirstName VARCHAR(100) DEFAULT 'RAJAT',
Course VARCHAR(100) DEFAULT 'MATHS')
Now , suppose for in some situation we need just default entry for example in my case I am just trying to insert 100 rows with default value so I need to write below statement
INSERT INTO #tmpStudent (FirstName ,Course ) VALUES (Default, default)
Now when I run the above statement. It insert default value of FirstName,course
I hope this might be helpful to you somewhere.