SEO aka Search Engine Optimization is a process of having a website come up higher in the search results when you search with a query or keyword. There are crawler based search engines like Google and Human based directories

Now lets see how a Crawler based search engine works

Crawlers or Spiders are automated robots that crawls the web constantly to find new websites and links. The spiders visit the site whenever there is a new site is built and online. Depending on the popularity and recency of the update of your site, the crawlers visits the site. The more fresh content a site has, the more often the crawler will visit the site, what does this mean to you? Well if you have a website for a while or may be a new site, it is very important for you to update the site often, this does not necesssarily mean that you have to change the look and redesign the site often, it means that you have to have fresh content or the copy or the message which you are conveying to the visitors.

How can you add content?

You can add content if you have a press release or add more pages, give related articles, if there is something new with your company add that in your site, Create a seperate page for news, artciles, blogs and resources, keep posting new and interested articles and writing there in those pages, add links to your site, point to trusted sites, get links from trusted sites.

Lets say if you are expert in your field, write articles and post those articles in the site. There are tons of ways to add fresh content to your site. This allows the spiders to visit your site more often because the spiders can understand that your site is updated often.
For example: If you have a website for Bad Credit Mortgages in Sarasota Florida. you can talk and write articles about Bad Credit, Mortgages, Sarasota and a combination of all of these as well and post an article ans tell the visitors how to apply for Mortgages and to people with Bad Credit to How to Apply for Mortgages in Sarasota Florida.

Now once the crawlers relialzes that your site is updated often, it will visit your site often and now it know and what the spiders do is, It takes a snap shot of your website, it crawls your website remember it will only crawl if you allow the crawlers to crawl your site, you can also restrict the crawlers not to visit your site, So once you have the crawlers visit your site, it looks at your Page Title, Description, HTML tags and then it stores in the database. Now whenever some search for that keyword, it goes back to the index, (the place where it stores the sites in alphabetic order) and looks at the most relevant site using algorithm or formulas such as Keyword in the Title, Description, Copy a good Meta tag, Good links from and to other trusted sites. Freshness and all other formulas and then list the results.

So when we search for something like Sarasota Mortgage for People with Bad Credit or XYZ the crawlers are not giving you live websites, but takes it from the database. So if you consider a good ranking result, first your site need to be crawled by the spiders.