First of all in order to discuss how SEM and SEO are different, we must first define each of them. By defining these two terms it will be much easier to illustrate how they are different and how, as an online business owner, you need both to succeed online. SEO - Search engine optimization. This is the method of using a variety of tactics to improve and influence your rankings on search engine results in a positive way so that your website appears near the top or at the top of the results page when a user performs a search which includes the keywords associated with your website and brand. SEM - Search engine marketing is the method of marketing via search engines. This also involves tactics and it ensures that you are visible to those who are searching with keywords that are associated with your business brand. SEM can also help to influence your ranking on the search engines but it comes after SEO in terms of over-all ranking influence. SEM involves formal marketing campaigns and tactics which are performed on search engines. For example, pay per click and Good Adverts and Good AdWords. Write attractive description tags that best suit to your business. Use powerful words and sprinkle thoroughly in the sentence as it will be the always be the first to appear on the search engine whenever a viewer try to make a search. Your description tags should be as precise as it could be. Make paragraphs short, so they are easier to read. Because there are seemingly endless sources of opinions and information on the Internet, readers are quick to dismiss articles that do not get to the point quickly.