Master Key
Master key -The master key is used to derive all keys for your account, including the owner key. If someone has access to your master password, they can steal your account and all of the tokens in it. So you must store it safely
Owner Key
Owner key-The owner key is only meant for use when necessary. It is the most powerful key because it can change any key of an account, including the owner key. Ideally, it is meant to be stored offline, and only used to recover a compromised account.
Active Key
Active key -The active key is meant for more sensitive tasks such as transferring funds, power up/down transactions, converting Steem Dollars, voting for witnesses, updating profile details and avatar, and placing a market order.
Posting Key
Posting key -The posting key allows accounts to post, comment, edit, vote, resteem, and follow or mute other accounts. Most users should be logging into Steemit every day with the posting key. You are more likely to have your password or key compromised the more you use it so a limited posting key exists to restrict the damage that a compromised account key would cause.
Memo Key.
Memo key -While transferring funds this key is used to encrypt and decrypt memos.
How to Transfer STEEM
Yes I know how to transfer STEEM
To do this you have to login with your active key then click on steem
As shown in the screenshot below..
Then you will click on Transfer and enter the amount and the user you want to transfer to and the required memo
Click on "Next" to complete the action
How to Power up
Yes I know how to power up.
Login with active key and click on STEEM, select "Power up" as shown in the screenshot below
Then enter the amount of STEEM you want to power up and click on "Power up"
Conclusion
Security in steemit should not be taken for granted.
All the keys are very important.
I have back it up offline and keep them safe.
I want to thank everyone for their supports