taken from the documentation on Seagull.

Entities are simply the basic content objects of your application, the data structures you’re going to be working with.  If you already know about entities, please skip down to the DB_Dataobjects section.

What are Entities?If you’re building a basic web app, let’s say a blog, then you’re likely dealing with some of the following entities:

• article
• comment
• user

What about article date, or user name you ask?  These are attributes.  Note that entities are always referred to in the singular. For more detail on the difference between entities and attributes see this article.  Another concept that goes hand-in-hand with entities is collections, which as you might have guessed are lists or collections of entities.  Examples of collections: all the articles on your homepage, all the comments assoicated with an article, all the results from a particular search query.