achievement 2-@mohammad9-task:basic security on steemit

hello friends how are you all?hope you are fine i am fine support, welcome my another post.
basic security off steemit.

MY POSTING KEY:
this particular key is used for social networking action, like posting, commenting and voting.this key has a limit set of permissons.
my posting key is permitted to do the following:
1.publish a post or comment.

1. edit a post or comment.
   3.upvote or downvote.
   4.follow people etc.

active key:
active key permissions
active key is used to
1.transfer tokens.
2.sbd conversion.
3.certain profile change.

1. vote for witnesses.
   5.create a new users.etc

owner key:
owner key is used to:
1.recover your account.
2.decline voting rights.
3.reset owner,active and posting keys.

memo key:
memo key is used to:
1.send an encrypted massage.
2.views an encrypted massage.

Finally I understand all about security.
And all my steemit friends are saying if you don't understand, you must comment.
thanks everyone.