Search engine optimisation (SEO) is probably still the most important thing to remember when conducting online marketing activity (though social sharing is catching it up quickly). If you want your content to be indexed correctly and make it to the top of the search results then understanding SEO is the key.
Being an IT-based subject, SEO has lots of acronyms and unusual terminology to help confuse outsiders. This can make it harder for marketers to understand the intricacies of SEO and to help out Marketing Donut have put together an SEO glossary detailing some of the main SEO terms you need to understand and allowing you talk to your web designers like a pro.