In the Online Business ER Diagram below, we see the entities like User, Services, Feedback, Complaint, Payment, and Admin. As shown below, an online business entity-relationship diagram (ERD) shows the relationships of entity sets stored in a database. An entity in this context is an object, a component of data. In simpler words, it is the basic design upon which a database is built. ER diagrams specify what data we will store: the entities and their attributes. They also show how entities relate to other entities. These entities have different attributes, like Admin: Email and Password; Services: Experience, Email, Address, Fee, Name, Info., Phone Number, Order ID, User ID, Push ID; Payment: Push ID, Payment Gateway, Fee; Complaint: Complain Message, Sender Email, Receiver Email, Push ID, User ID, and more.