It's no problem- it's very confusing!
Ameraucanas are a pure breed of chicken that come in a few standard colors. They all have muffs, they all have a set body structure, and all Ameraucana hens lay blue eggs, and blue eggs only. They're breed you can show, because they're pure, and they're pretty expensive- think about $18 a chick. They're also pretty hard to find; much more common are...
Easter Eggers aren't really a breed. They're colorful mutts with some ameraucana or other blue-egg-laying heritage, but with EEs you never really know what you're going to get. They can be any sort of cross, and so colors, patterns, and body size and shape all vary greatly. The often, but not always, have muffs, and some have feathered feet. You can't show them, and when you breed two you never really know what you're going to get. Depending on what crosses they came from, hens can lay any color of egg, although green and light blue are most common. They're very easy to find- most feed stores carry them, and you can get them at just about every online hatchery, and they're relatively cheap (~$3 per chick). Sometimes feed stores and hatcheries will label EEs as 'Americanas' or straight up 'Ameraucanas', but generally assume that unless you can be absolutely assured of their heritage, they will be a mixed breed.
Hope this helps!