First thing to do when you come to Steemit. Beginner walkthrough. Pt1

What is the very first thing a new Steemian should do? Post your first comment? Read the top paid posts to learn how to earn rewards? Upload your profile photo? The answer is, none of the above! The very first thing is: write down your master/owner keys on a piece of paper, and keep the paper in a safe, secure place.
Anyone can use your password to log in, to transfer money, to comment on others, and fish your friends. What would you call it? 'Master/owner key' is not enough. We would call this long string 'Steem ID's Life'. If stolen, dead.
We warn every new Steemian: NEVER, EVER use your master/owner key when logging in to Steemit! ALWAYS login with your posting key. It is sufficient for everyday use.
If you are doing something related to your Steem Wallet, then use the active key.
When do you use your master/owner key? Only when you want to recover something. Take it as the 'restore to factory settings' option on your smartphone.