Logical Data Model

The logical data model describes how data objects relate to each other, but is independent of the technology or database management system used. Logical data models typically show entities (e.g. a patient, an appointment, a result), relationships (e.g. an appointment is linked to a patient via a unique identifier), and attributes (information that is useful to further describe the entities)

Simplified Definition

A Logical Data Model shows the relationships between different items of data. For example, for a simple online stationery shop, a Logical Data Model might show that a customer is one data item, and the customer can be related to a number of products in the online shop via the customer orders. This might be represented in the following simple Logical Data Model:

Each customer order has one customer, and one or more products. It can be further illustrated:

Useful links

https://www.gooddata.com/blog/how-build-logical-data-models-scale-analytical-applications/

https://en.wikipedia.org/wiki/Data_modeling