- Reel - that is the full reel as component manufacturer creates it and sells it to component suppliers
- Cut tape - this is smal piease of tape which was cut off Reel (good for small quantities and hand prototyping). Cut tape can be used also for assembly in assembly house, but they do not like it much (they prefer reels).
- Digi Reel - if do not want to buy the whole reel, but you still prefer to have components on reel (because you need it for your mass production), in Digikey they will take the reel from supplier and they will rewind the number of components you need, so you will get a Reel with number of components what you need (very simply to say, instead of buying 3000 components on the whole reel for 3000USD, you ask digiky to send you reel with 500pcs).
This article may help: