The Internet across the globe. No matter where the data actually lives, the Web will send a copy of it to you. This horrible piece of techno-babble simply means that the information on the Web is linked by association of content. When you browse and borrow from a library you are physically accessing the information. You don't have to return it as you would a book.
Clients get copies of documents from servers.
If you know how to find your way around in one library, it is pretty easy to learn how to use another. The Web is designed in such as way that the information it contains can be accessed by anyone connected to the Internet with a Web client, or browser, no matter what kind of computer system they are using - Mac, PCs or Unix. One copy of the information is sent and the client software does the work of making it look pretty much like what it would look like on any other computer system. So we can say the Web provides universal access to its library materials. The Internet has been around for quite a while and a number of different kinds of services have evolved on it.