This part of memory is used to store all the changes that occur in the database. It is essentially a staging area for all the changes that have been made to the Database Buffer Cache through Server Processes. These changes are then written to disk (log files) by the LGWR (Log Writer) process in the following cases:

1. When a user performs a Commit Transaction, the log buffer is written to disk.
2. Every three seconds.
3. Before DBWn (Database Writer) operations.
4. When the log buffer is full (reaches a threshold).

The size of the Log Buffer is controlled by the LOG_BUFFER parameter. This parameter is static, meaning its value cannot be changed without shutting down the database. By default, the size of the Log Buffer is tied to the Number of CPUs in the system. For example, if CPU_COUNT is 1, the Log Buffer is typically 256KB, but if CPU_COUNT is 8, the Log Buffer size is usually 2MB.