Oracle Database is a relational database management system (RDBMS) which is used to store and retrieve the large amounts of data. Oracle Database had physical and logical structures. Logical structures and physical structures are separated from each other
What is schema?
A user account and its associated data including tables, views, indexes, clusters, sequences,procedures, functions, triggers,packages and database links is known as Oracle schema. System, SCOTT etc are default schema's. We can create a new Schema/User. But we can't drop default database schema's.
What is a Tablespace?
Oracle use Tablespace for logical data Storage. Physically, data will get stored in Datafiles. Datafiles will be connected to tablespace. A tablespace can have multiple datafiles. A tablespace can have objects from different schema's and a schema can have multiple tablespace's. Database creates "SYSTEM tablespace" by default during database creation. It contains read only data dictionary tables which contains the information about the database.
What is a Control File ?
Control file is a binary file which stores Database name, associated data files, redo files, DB creation time and current log sequence number. Without control file database cannot be started and can hamper data recovery.
Define data blocks ?
Data Blocks are the base unit of logical database space. Each data block represents a specific number of bytes of database space on a disk