Three file physical structure of Oracle

.dbf data file, the file is a database for storing data, such as records in the table, indexing, data dictionary information and the like, can DBA_DATA_FILES view information through a system data dictionary. And a logical point tablespaces (not a real file) corresponding to a table space can have multiple data files, but only a part of a data file tablespace.

.log redo log files, modify the information for the record to the database (query does not produce). Log files are an important means of backup and recovery.

.ctl control file that describe the physical structure of the database. Storing data files and log files and other information.