Oracle Schema

1. A schema is like a separate instance of database normally associated with one particular database user. This username is called the schema owner, or the owner of the database instance. Each schema is a collection of different database objects. 

2. A database object is any structure in a database that is used to store or reference data. Some examples of database objects include tables, views, clusters, sequences, indexes, and synonyms. 

3. Schema can consists of any number of tables or any number of objects up to the limit set by database implementation. 

4. Table names in same schema should be unique and can have same name from another schema.