Active key
With the help of password you can apply to your work and perform social activity. For example, you can post, vote on any post, follow someone, etc.

This statement is false. You use the posting key to log in to your wallet and not the active key.

I invite you to read the informative post below about he explanation of the achievement 2 to be able to understand more:

https://steemit.com/hive-172186/@cryptokannon/basic-security-on-steem-achievement-2-mentor-by-cryptokannon