REST architecture basically utilized URI for a restricted set of operation done via HTTP vocabulary. The most common vocabulary is GET, POST, PUT and DELETE. In my current project we need to have a simple way to store and retrieve PDF documents via a web server.
You might ask why I choose to use REST and not simply code a simple PHP upload script. Currently where I work its often difficult to add or install application to a server. I have a web server on Server#1, in which storage is limited and I can't use it to store files other than web pages/scripts. I have another server Server#2 which is a database and processing server that has large amount of free space but doesn't have any web server on it. So I think why not make a simple web server on Server#2 and expose POST/GET API to store/retrieve pdf.
I use Restlets, a simple REST framework build with Java. Using Restlets every URI is represented with a Resources class which will return a Representation if called. For this project I have two REST URI
http://server/docs/ (POST)
http://server/docs/{documentName} (GET)
Its very simple, if I want to upload a document I just need to do a POST with form and <input type="file">. If the operation is successful it will return the file name. For download I would just do a usual get to the specified URL e.g.
GET http://server/docs/sample.pdf HTTP/1.1
or I would just direct my browser to the specified URL. I add a simple listing if you direct your URL to http://server/docs/