SEO is the process of improving a website to rank higher in search engines. The basic purpose of SEO is to increase website traffic for targeted keywords. People typically find a website either through a search engine or reference link. The two most popular search engines are Google and Bing. Yahoo is powered by Bing.
People type keywords into search engines to find information related to those keywords. If a website is optimized with those keywords, it will rank high in the results of a search engine query. Other websites with similar keywords compete for those rankings. It is important for a website to be optimized with keywords that are effective and accurately describe the business or organization. Keyword focus should be based on product or service, location of business, and company brand.
There are 2 basic areas of SEO, On-Site and Off-Site. Both are important, but On-Site SEO should be done first.
1. On-Site SEO: The process of improving the internal structure and organization of a website. The HTML code must be organized with the proper use of HTML tags and placement of keywords. It is important to select the right keywords and place those keywords with prominence throughout the website. Google has over 200 signals in their algorithm that determine the relevancy of a website.
W3C validation checks for technical errors on each page of a website. The W3C declares standards and guidelines on the WWW (World Wide Web). Websites must be declared with a document type for W3C validation. This allows for proper website accessibility and effective SEO.
An XML Sitemap is a hidden page on a website that defines the navigation structure of a website. A sitemap helps search engines index and update each web page properly, and in order of importance.
2. Off-Site SEO: The process of marketing and maintaining a website. This may include business and map listings, search engine and directory submissions, analytics, blog marketing, social networks, and link reciprocation. Off-Site SEO is an ongoing process and typically part of a monthly plan.
Read Google's official SEO Guide.