Sinoatrial node. The sinoatrial node (SAN; also known as sinus node) is a group of cells located in the wall of the right atrium of the heart.
How Do Web Browsers Work? The World Wide Web is a system of Internet servers that support specially formatted documents. Web browsers are used to make it easy to access the World Wide Web. Browsers are able to display Web pages largely in part to an underlying Web protocol called HyperText Transfer Protocol (HTTP).
Types of Internet Protocols. There's more to the Internet than the World Wide Web. When we think of the Internet we often think only of the World Wide Web. The Web is one of several ways to retrieve information from the Internet. These different types of Internet connections are known as protocols. You could use separate software applications to access the Internet with each of these protocols, though you probably wouldn't need to. Many Internet Web browsers allow users to access files using most of the protocols.