What is the use of ALERT log file? Where can you find the ALERT log file? | Oracle DBA

The ALERT log is a log file that records database-wide events.
The information in the ALERT log file is generally used for trouble shooting.
Following events are recorded in the ALERT log file:
i. Database shutdown and startup information
ii. All non-default parameters
iii. Oracle internal (ORA-600) errors
iv. Information about a modified control file
v. At log switch
The location of ALERT log file is specified in the BACKGROUND_DUMP_DEST parameter.