Hand A holds 8½ losers : 2 each in ♠, ♥ and ♦, and 2½ in ♣.

Hand B holds only 7 losers : 1 each in ♠ and ♥, 3 in ♦ and 2 in ♣.

Hand B has three additional advantages :

1. It has two 4-card major suits
Holding 4 cards in both major suits represents of course a good chance that you will find a 4-4 trump fit with your Partner in one of them.

2. It has "supporting Honours" in both those two suits
When you hold 2 or more Honours in the same suit, the suit (and the hand) is strengthened considerably, especially when the Honours are touching (AK, KQ) or only 1 space apart (AQ, KJ).

3. It has a doubleton suit (in clubs)
Holding a doubleton usually ensures an extra trick provided you find a trump fit with Partner in one of the other suits.

Normally you always make an opening bid with 13 (or more) points. But holding 12 points you can open the bidding provided you have only 7 losers.
Therefore with Hand A above you would pass initially (hoping your Partner will open the bidding), but with Hand B you can confidently make an Opening bid yourself.