Oracle redo log buffer cache vs redo log file While going through the Oracle architecture I got stuck with the below question. Could someone help me answering this?

Why do we need both redo log buffer cache and redo log files? Why can't we write the data directly to redo log files from database buffer cache?
Redo Log Buffers: A log buffer is a circular buffer in the SGA that holds information about changes made to the database. This information is stored in the redo entries. Redo entries contain the information necessary to reconstruct or redo changes made to the database by insert, update, delete, create, alter, or drop operations. Redo entries are primarily used for database recovery as necessary.

Redo Log: The most crucial structure for recovery operations is the redo log, which consists of two or more preallocated files that store all changes made to the database as they occur. Every instance of an Oracle Database has an associated redo log to protect the database in case of an instance failure.

for more information about database structure please refer to https://docs.oracle.com/en/