What is Block Change Tracking in oracle database?

Block Change Tracking is a file created in the same location path as the datafiles and helps to tracks the
blocks changed since the last incremental backup.

Block change tracking helps us to save time during an incremental backup just by checking only the affected/changed blocks.

And here are the steps to configure Block Change Tracking:

SQL> conn sys/orcl@to_primary as sysdba
Connected.
SQL> SHOW PARAMETER DB_CREATE_FILE_DEST;
 NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_create_file_dest                  string

---Setting  DB_CREATE_FILE_DEST initialization parameter to the correct location
SQL> ALTER SYSTEM SET  DB_CREATE_FILE_DEST='D:\app\Admin\virtual\oradata\orcl'
  2  ;
 System altered.
SQL> SHOW PARAMETER DB_CREATE_FILE_DEST;
 NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_create_file_dest                  string      D:\app\Admin\virtual\oradata\o
                                                 rcl
                 
---Enable block change tracking										 
SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;
 Database altered.
SQL>