Defining Search Engine Optimization and Search Engine Marketing

Knowing the difference between search engine optimization (SEO) and search engine marketing (SEM) is crucial in getting the best result on search engines.

SEO involves improving internal and external aspects of a website, to increase its organic visibility for search engines. SEO requires editing a website's HTML code and content to make it more search-engine friendly, and then promoting the site to increase its relevance on the Web. For more information, see What is search engine optimization and why should I care?

SEM refers to how you advertise your website on search engines to increase your visibility in search engine results pages. Use SEM as an alternative and/or supplement to SEO. Common methods of SEM include:

• Pay Per Click (PPC) — Lets you buy your way to the top of results pages for searches relevant to your business. An advantage of PPC is it's controllable: You set the budget and then specify the words and phrases to target. With PPC you identify the exact page you want your ads to link to, and you can turn the ad off at any time to conserve expenditures for peak periods.
• Social Media Marketing (SMM) — Uses social media outlets for marketing and public relations purposes. SMM uses social media networks (Facebook®, Twitter®, MySpace®), social media sharing (YouTube®, Flickr®), and social bookmarking (Digg, StumbleUpon) to generate excitement around your brand and services.
• Contextual Advertising — Targets a Web page based on the page's content, keywords, or category. Contextual advertising is most commonly seen on a website as a banner or pop-up ad. Publishers and advertisers only profit when a visitor clicks on the ad.