in the documentation https://www.lucidchart.com/pages/er-diagrams it states
Entity type: A group of definable things, such as students or athletes, whereas the entity would be the specific student or athlete. Other examples: customers, cars or products.
Entity set: Same as an entity type, but defined at a particular point in time, such as students enrolled in a class on the first day. Other examples: Customers who purchased last month, cars currently registered in Florida. A related term is instance, in which the specific person or car would be an instance of the entity set.
And that seems to be misleading. Entity type is more akin to a Table name or a definition, but entity set is a set of concrete records.
