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).
The default browser is the web browser that is automatically used when opening a web page or clicking on a web link. This document explains how to choose the default browser for both Windows and OS X. 1  In Internet Explorer, go to Tools (gear icon) > Internet Options.  Click the Programs tab.