Stored procedure is some SQL (PL/SQL) code stored on the server. PL/SQL is language, I think extension of SQL, there are added some procedural features to SQL.
Go through Oracle documentation, I'm sure there is exact explanation.
Go through Oracle documentation, I'm sure there is exact explanation.
Indeed there is. It is called the "PL/SQL User's Guide and Reference" and you'll find it (plus links to many examples) in the documentation that came with Oracle.