Entities
According to Merriam-Webster, an entity is "something that has separate and distinct existence and objective or conceptual reality." A more practical description would be something that you want to store characteristics about. When you sell products to customers, you need to keep track of certain characteristics or properties of those products. At a minimum, you need to know the price that the product sells for. So here, the product is an entity and the price is a characteristic of the entity. Attribute is another often-used word for a characteristic or property.
Entities translate easily into tables. For each entity that plays a role in a process, we create a separate table in the database. Each characteristic or attribute that you need to keep track of will become a column in the table.
Using the term entity is not completely accurate (but it is a term in everyday use). Most of the time, we mean entity type when we say entity. An entity type is a generic...