search engine optimization (SEO) is the process of improving the volume and quality of traffic to a web site from search engines via "natural" ("organic" or "algorithmic") search results for targeted keywords. [Wikipedia].
SEO is a simple concept with complex methods and even more important consequences. The idea behind SEO is that you make your web site more 'friendly' to search engines. The result of good SEO is that your site not only shows up higher in the search results, but also better matches the kinds of key words your ideal visitors will be using to find you.
take for instance fictional Le Art Cafe, an art gallery in Edmonton, Alberta that specializes in local artists but also has a coffee shop. For them, when a person in the world searches for 'art gallery' or 'local art', it would be nice but not especially critical if Le Art Cafe web site comes up first, since the majority of people won't be looking for Le Art Cafe. Now, if people in Edmonton search for 'art gallery' or 'local art' or 'trendy place to hang out in Alberta', Le Art Cafe would definitely want to show up.
while we don't want to bore you with the details, the basics of SEO are these:
there is of course much more to it, but this should give you an idea of how involved SEO is in creating your web site.
it is also very important to note that nobody can guarantee your placement in a search engine for anything but the most specific search terms (i.e. your company's name, and then only if it is fairly unique). If any company tells you different, visit the Google SEO guidelines for advice from the ultimate source.
there are two ways to achieve SEO, whitehat, or ethical design that understands how search engines work, and blackhat, where less-than-honest methods take advantage of how search engines work. While both may work, and the latter may work better in the short term, it doesn't always work out in the long term. We at CT only use ethical, search engine-friendly methods to achieve SEO.
if you want to read further, consider the following resources: