Canonical tags- Canonical tags are HTML tags which are used when there is duplicate content on website which leads to PR leak. Suppose there are two URLs which redirects to same page, rel="canonical" tells the spider which one out of them is the main page in case of duplicate content. A/B Testing- A/B testing is a way to carry out random experiments. In reference of SEO, it is simple way to test change to your website layouts or content and check which of the changes made results into increased conversion / performance. Omniture- It is just another website analytic tool like Google Analytics. Omniture was acquired by Adobe in the year 2009. Hope this helps.