Lock code is also known as security code or password.
The lock code helps you protect your phone against unauthorized use. You can set your phone to ask for the lock code that you define. Keep the code secret and in a safe place, separate from your phone.
If you forget the code and your phone is locked, your phone will require service. Additional charges may apply, and all the personal data on your phone may be deleted.
For more info, contact the nearest authorized service facility for your phone, or your phone dealer.