Anatomy of a one-shoulder baby sling
shoulder (padded or not) - sits spread over either shoulder.
pouch or pocket - where the baby lies/sits.
rails (padded or not) - are the top edges of the pouch.
knot or rings - hold the baby sling closed and are to be in the front of your shoulder where you can reach them.
tail (sewn or not) - is the fabric that hangs from the knot or rings and is used to adjust the sling. if there is a long enough tail, it can be used for breastfeeding privacy ( . . . if that matters to you. don't be shy on our account!).
Anatomy of a wraparound baby carrier
this one is very simple, but it stills helps sometimes to have it spelled out. Most wraparound style baby carriers (Moby Wrap, Girasol, Didymos, Hug-a-Bub, Baby Bundler, Ultimate Baby Wrap, Boba Wrap) are just one long strip of cloth, 18-30" wide, made of different types of fabric.
Anatomy of a chinese-style baby carrier
this style of baby carrier varies quite a bit in the details, but has the same basic components, shown above. variations include: padding in shoulder and/or waist straps, angle of shoulder straps, width of straps, buckles. examples of this are: Catbird Baby Mei Tai, Babyhawk Mei Tai, Freehand Mei Tai, Napsack baby etc.