In Magento 2, EAV stands for Entity-Attribute-Value, a data model that stores complex data structures. The EAV model consists of three database tables: entity, attribute, and value.

EAV is used to accommodate the various types of product attributes and the variations between products in a flexible way.

Entity: The entity table stores information about the described entity (such as a product or customer).

Attribute: The attribute table stores information about the attributes of the entity (such as product name or customer email, price, or any other property that describes the product),

Value: The value table stores the actual values of the attributes.

One of the main advantages of EAV is that it allows for a large number of attributes to be stored for each entity without requiring a large amount of storage space. This is because only the attributes with values for a particular entity are stored in the value table rather than every possible attribute.

In Magento, the EAV model plays a crucial role in allowing for the creation of custom attributes and attribute sets, which can be used to tailor the product catalog to specific industries or use cases. It also provides for the creation of custom customer attributes, which can be used to store additional information about customers. Overall, the EAV model enables a high degree of customization and flexibility in Magento, which is essential for many e-commerce businesses.

I hope this information was helpful to you.