Entity:

An entity represents a real-world object or concept that is being managed in the SAP system. For example, the entity "Material" represents a material used in the manufacturing process.

Field:

A field is a specific characteristic or property of an entity. For example, the field "Material Number" is a field of the entity "Material".

Attribute:

An attribute is a technical representation of a field within the SAP system. It defines the data type, length, and other technical properties of the field. For example, the attribute "MATNR" is the attribute that represents the field "Material Number".

To recap,

an entity is like a blueprint, a field is a specific feature of that blueprint, and an attribute is the technical implementation of that feature.

Here is an example to illustrate the concepts:

Consider a "Customer" entity in SAP MDG. The entity "Customer" represents a customer of the company. The entity has several fields, such as "Customer Name", "Customer ID", and "Customer Address". Each of these fields has an associated attribute, such as "KUNNR" for "Customer ID" and "NAME1" for "Customer Name".

So, in this example,

"Customer" is the entity, "Customer Name" is a field, and "NAME1" is the attribute.

Thank You,
Suggu Sandeep.