First vs FirstOrDefault in LINQ

First vs FirstOrDefault in LINQ

S.No	First	FirstOrDefault
1	Gives first record from the collection, if collection doesn't have any object then throws error.	FirstOrDefault extension method is used to retrieve the first element from the collection, if not then gives null

LINQ To SQL and LINQ To Object

LINQ To SQL and LINQ To Object

S.No	LINQ To SQL	LINQ To Object
1	needs a Data Context object.	doesn’t need any intermediate LINQ provider or API.
2	returns data of type IQueryable.	returns data of type IEnumerable.
3	translated to SQL by way of Expression Trees, which allow them to be evaluated as a single unit and translated to the appropriate and optimal SQL statements	does not need to be translated.
4	translated to SQL calls and executed on the specified database.	executed in the local machine memory.