Node: An entity (we can think of it as a page, although it can be displayed in other ways too) associated with a content type. Content editors create nodes to build the site.
Content Type: An entity type that has defined fields. Developers create content types and define the fields.
View Mode: Each content type can have various view modes. This is a way of outputting a node in a specific format with a specific set of fields. What we're calling a Preview is a view mode. So a preview is a pre-defined way of outputting a node that can be used all over the site. View modes are built by developers and are not configurable by content editors, but they can edit nodes to change the content of a preview. Another good example of a view mode is "search result" which will define, for each content type, how to display that content on the search page.
Paragraph: An entity type that has defined fields, just like a content type, except paragraphs are not nodes and do not have their own pages. Paragraph types are defined by developers. Individual paragraphs are created by a content editor within a single node. Content types can have Paragraphs fields that allow content editors to add a variety of paragraph types to a node.
Vocabularies: A vocabulary is basically a taxonomy type. It is similar to a content type but, often, vocabulary terms do not have visible pages. They are meant to be "tags" for content rather than pieces of content themselves. There are exceptions to this, for example, Academic Area is a vocabulary whose terms have visible pages. But, we want to be able to tag content with these academic areas, so it makes more sense for it to be a vocabulary than a content type.
Views: A group of content that is filtered by specific parameters and output in a specific view mode. Views are built by developers and are not easily configured by content editors. A view is basically a database query. For instance, for the view of events on the MBA Events page, we'd create a view with the following specifics: Content type == "Event" Event Type field value == "MBA" Sorted by soonest Content output in the "Event Preview" view mode
One more note about the "Entity Based" content: All of the items with the word "preview" in them are view modes because they display a single node in a certain format. The last 2 items, the navigation blocks, are views because they display a list of content filtered by certain parameters.