Stayman & Transfers
These two conventions work closely with 1NT & 2NT openings. There are similarities and differences.
The similarities are that the point range responder shows when using either Stayman or Transfers is wide-ranging, and unlimited.
So, to respond Stayman (2♣) to 1NT openings may show a weak (0 - 7), intermediate (8,9) or strong (10+) hand.
Because opener MUST reply to Stayman, the responder will show their exact strength and shape at their next turn. That's why it could be wide-ranging.
Same with Transfes: because the bid of the suit ranked below the suit you actually hold is the way to transfer, there will always be another round of the bidding and responder will be able to show the strength and shape later. So transfers too, show weak, invitational or strong responding hands.
Transfers don't interfere with Stayman, because 2♣ over 1NT, even if you are playing transfers, is always Stayman. 2♦ would be a transfer to hearts, 2♥ a transfer to spades, 2♠ a transfer to clubs, and 2NT a transfer to diamonds, but 2♣ is never a transfer. Ditto with 2NT openings.
The main difference between these conventions is that one asks and the other tells.
Stayman (with a four-card major/s) asks about partner's holding in the majors, and transfers (never fewer than five cards in the suit) tell partner that you have a long suit, and want partner to decide whether to play in your suit or in no trumps.