Unique Identifier in sql server

Unique identifier is used to create an unique 32 bit column value in the table. NewID() is a system function used to generate unique identifier value. It will take millions of years to generate a duplicate Unique identifier value
I am using NewID() to insert the data,

Code Snippet

DECLARE @VenkatTableVar table ( RowGUID uniqueidentifier PRIMARY KEY,VenkatName sysname,Name varchar(20)) INSERT INTO @VenkatTableVar1 VALUES (newid(),'Venkat','VenkatName') SELECT * FROM @VenkatTableVar

Tried with manual data into the unique identifier column,

Code Snippet

DECLARE @VenkatTableVar table ( RowGUID uniqueidentifier PRIMARY KEY,VenkatName sysname,Name varchar(20)) INSERT INTO @VenkatTableVar VALUES ( cast( 'A8FB1E48-F129-44RC-82AE-001EAD5A8ADE' AS binary ), 'Venkat','VenkatName') SELECT * FROM @VenkatTableVar