If you are new to Drupal then you may be a bit lost with all of the terminologies around it. Content Types, Fields, Blocks, Beans, Modules, themes, etc. I hope to go over some of the common ones in 2020, what they mean and how they are used in various ways. Check back on this page as we will likely add more terms as time goes on.
A field allows you to create elements on a node that take specific types of data, this can be images, videos, files, phone numbers, or references to other types of content. It is one of the things that makes Drupal so flexible. It takes careful planning and documenting to understand the workflow/fields that would be needed to make a good interface for end-users.
A node is kind of the catchall phrase used when we are talking about any type of content. Drupal is a bit different fro WordPress or some of the other CMS platforms in that it lets you create different types or Content Types, that can then be used to create structured pages. If done right this creates an easy to use interface for site owners to create great-looking pages over and over again.
A block is a smaller piece of content that can be placed on the pages for nodes, users, or other pages. It can be useful things for like lists of content/call to action elements, and other items of content that are not designed to be on their own when displayed to users. They are similar to Nodes, in that you can add Fields to them in order to control how the output is displayed.
An entity is the catchall word for any type of item in Drupal, this can be a Node, Block, User, Product, etc. They are extremely flexible in that you can create new custom entities in Modules to represent new types of things on your site.
A paragraph is a new type of field added to Drupal it is useful for handling situations where you want to have a field that contains multiple-sub fields for a node or block. A great example of this is Phone numbers, so you could have a Phone number field that allowed you to enter the phone number, or you could have one that allowed you to enter the number as well as the type of phone number it was for a contact, ie Work/Home/Cell/Fax. This adds even more flexibility on controlling layout.