A Search Engine is not an engine in the normal sense, but it is actually a software program that searches websites, documents, images, and even videos for specific keywords. It returns a list of results where the keyword or search term you typed were found. A Search Engine is actually a system, the system which is made up of the hardware and software components of a computer. Google and Yahoo are considered systems because they are computers with software running on them. Search Engines are very complex and the search algorithms are updated continuously.
Search Engines use computer robot programs called spiders to gather and store the information you’re searching. Spiders find the pages and then pass the information on to another program for indexing. The spider identifies the data and then stores it in the search engines database. The spiders crawl the web and find information about content by following other links that have previously been crawled. This is why it’s important to have links to useful content on your website, and also have other website link back to you. This process of linking is called reciprical links, or back linking. If you launch a website, but never link to other pages, your site will more than likely not be found by the spiders. If your page has fresh content on it, then the spiders will find you eventually, although it takes more work and you have to manually submit the new Uniform Resource Locator to the search engines indexing program.