Canonical Tags

Tags used to tell Google which page is to be used for indexing in the result of duplicate pages. For example, a single piece of clothing in small, medium and large that is listed on a website in three different URLs.

Other Definitions

LSI

Latent Semantic Indexing - the process of using common words…

Optimisation

The physical process of improving a page for search engines.

Link Exchange

Pairing with a website to link to each other, often…