Indexing and caching
Today's search engines have started measuring rendering times — the time it takes for a web page to download, including graphics and other files — as part of their ranking algorithms. In the past, we used to concentrate on download speed because so many users were connected to the Internet with slow, dial-up connections. With the proliferation of broadband speeds, most developers eased up on this goal, opting to include more flash animations, larger graphics, and complex JavaScripts. Now, we're moving back to the beginning in order to satisfy Google, Yahoo!, and Bing.
With Magento's complex MVC architecture and database structure, you can have the most efficient front-end design possible, yet still experience very slow download speeds as Magento works to build the pages and query the database. Therefore, to create a site with the lowest download speed, we need to take advantage of two important tools: indexing and caching. Each contributes its own benefit to your goal...
