How Can People Delete Their Facebook Account Permanently ??

To deactivate your facebook account is completely different from permanently deleting it, so keep that in mind. Deactivating means that your facebook account will still be there on the servers comprising all of your information, however your info, pictures, Timeline etc won't be searchable by anybody.
 

This becomes 101% private.

This could be reactivated at any moment with everything totally restored. Permanently Deleting your facebook account implies that your all user information will be fully removed from the servers and any snap or contact will also be permanently deleted. This can't be undone, once the fourteen period of expiry has passed. 

 

 

If you delete it, no one will be able to search it but facebook will keep it and some of its contents which had been shared with friends can be seen by other users. When facebook users discover that they should've not deleted their account, they could restore their profiles again.

 

Many people deactivate their accounts for casual reasons,” Facebook clarifies.

Fortunately for them, Facebook actually provides the method of deleting their accounts permanently. The feature has been accessible, However it’s not easy to find if you really don’t know where to search it. you'll be able to permanently delete your account via this link.

After using this link your account will still be there for you on facebook for some more weeks. During that period if you login to your facebook account you'll be able to get your data and if you don't all of your data will be permanently deleted.

If you think you'll never use your facebook account and want it deleted then don't login to your facebook account in that time.

This has been clarified in help page of facebook.