Explain the origins and the importance of them.
amazon.com was funded in 1994 by Jeff Bezos, it was called cadabra.com and was an online library, it had nearly 200.000 books, then it was renamed amazon.com in honor of the south American river, in that time the list were alphabetical so amazon were always in the first place.
the importance of amazon is not only sell any type of products furthermore it also give you cloud storage, clustering in cloud, messenger in row and many others, will give an added value, and also make amazon the biggest provider of integrated services
how they are used
Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides resizable compute capacity in the cloud. It is designed to make web-scale cloud computing easier for developers.
the amazon cloud storage is the place where you can save all the images you want
also is the common way to buy almost whatever item, sometimes with discounts, also you can preorder, all of this arrive to your home in most of the times three days