Returns the object ID of the specified object.
object_id(object_name)
select object_id("titles")
----------- 208003772
select object_id("master..sysobjects")
----------- 1
object_id, a system function, returns the object’s ID. Object IDs are stored in the id column of sysobjects.
Instead of consuming resources, object_id discards the descriptor for an object that is not already in the cache.
Transact-SQL Users Guide
sp_help in Reference Manual: Procedures
sysobjects in Reference Manual: Tables
ANSI SQL – Compliance level: Transact-SQL extension.
Any user can execute object_id.