The Entity-Relationship Model (ER Model) is a visual representation used in database design to illustrate how data entities relate to one another. In this model, an entity represents a real-world object or concept, such as a Customer or Product. Each entity has attributes, which are characteristics that describe it, like a Customer's name or a Product's price. Relationships in the ER Model show how entities interact with each other. For example, a Customer can place an order for a Product, creating a connection between these two entities. This model helps in organizing data efficiently, making it easier to understand and manage.