Here is a list of terms used in these Content type tutorials:

JargonExplained
Content type t4 term for stand-alone design elements
Existing content list List of Content types attached to a section 
Page layout t4 term for a page template
Responsive website Website that works on all screen sizes & types, eg. mobiles, tablets, desktop etc.
Section t4 name for a page or folder
Sub-section t4 name for a sub-page or sub-folder (Also known as a 'Child').
Site Manager The name t4 gives their CMS
Site structure Main t4 Site Manager screen, a view of the site structure and the starting point for building or adding to sections (pages). It can also be called the site tree.
Contributor The Contributor role gives you the right to add content; modify content, delete content and add to the Media Library
Moderator The Moderator role gives you the right to add content; modify content, delete content and add to the Media Library. Plus approve content, create a Site Structure and publish.
Power User The Power User role gives you the same rights as the Moderator, plus assign and create new users, publish sections, add workflows, navigation, templates and footers.
Administrator The Administrator role gives you the same rights as the Super User, plus manage users, styles, workflows and templates, assign and create new users, run reports, have Access Control and set configurations.