Search engines use an automated program called "webcrawlers" or "bots" to scan, evaluate and index the information on your website. There are key identifiers on each web page called "tags" that pass information to the webcrawler.
Search engine optimization is when you insert certain keywords or keyphrases in each of the tags to achieve a higher search engine ranking for the keyword you are targeting.
How To Optimize The Title Tag
A search engine index can be compared to a large library. Within each library are thousands of books, each with a title. When you want a specific book you search for the title.
The title of your web page works in a similar manner. It tells the webcrawler and search users what they'll find on your page when they click your link.
If you had a wedding photography business in San Francisco what would be a good title tag?
A poorly optimized title tag would be, "welcome to our website". There is no transfer of information to the crawler or user and the page can be about anything, so it will not rank well in the index.
A highly optimized title tag would be, "San Francisco Wedding Photography". It displays key information to the user, and will be indexed for some important keywords.
How To Optimize The Tag Description
When you run a search query there are several lines of information about your web page under every link. That information is dropped directly from your description tag.
Your description tag should be an accurate portrait of what is on the web page. A common mistake is to use the same description tag for every page of your website. Every web page is different, so every description tag should be unique.