Having a Look at What Search Engines See

What a search engine sees when it loads one of your pages is not the same as what your browser sees. To understand why, you need to know how a Web page is created. Here's a quick explanation:

1. A user types a URL into his browser, or clicks a link, causing the browser to send a message to the Web server asking for a particular page.

2. The Web server grabs the page and quickly reads it to see if it needs to do anything to the page before sending it.

3. The Web server compiles the page, if necessary.

In some cases, the Web server may have to run ASP or PHP scripts, for instance, or it may have to find an SSI (server side include), an instruction telling it to grab something from another page and insert it into the one it's about to send.

4. After the server has completed any instructions, it sends the page to the browser.

5. When the browser receives the page, it reads through the page looking for instructions and, if necessary, further compiles the page.

6. When it's finished, the browser displays the page for the user to read.

Here are a few examples of instructions the browser may receive:

• It may find a <SCRIPT> tag, telling it to load a JavaScript from another file — it must then request this file from the server.

• It may find JavaScripts embedded into the file, in which case it runs those scripts.

• It may find references to images or other forms of media, and have to pull those into the page and read CSS (Cascading Style Sheets) instructions to see how the text should be formatted.