Strong Opening 2's

If you play opening at the level of 2 is strong in all suits, opening opening 2♣  has a very different meaning than opening 2♠ 2♥ and 2♦. The rules are different for 2♠ 2♥ and 2♦ which are natural bids and again for 2NT which has  different point count and addresses distribution of cards in a hand.

Opening 2 Clubs.

A 2♣  opening bid is the strongest it says nothing about your club suit but promises a minimum of  23+ TP and is forcing partner to keep the bidding going until game is reached. Of course with 10 points partner will probably want to keep going to slam.

Opening 2♠ - 2♥ - 2♦ shows less points then a 2 Club bid, usually 17-22 HCP better than 8 or 9 playing tricks but not enough for 2♣. Usually these bids show a good suit, partner is not forced to bid game, but depending on partners cards and point count decides whether to end in part-game, game or slam.

Opening 2NT.

Opening the bidding with 2NT tells partner you have 20-22 HCP and a balanced hand. This is not a game force bid. Partner can Stayman, make a negative takeout bid or can bid game or slam.