A relational data model in DBMS is a collection of data items with relationships between them. The relationships are represented by links, which are called keys. A key is a way of uniquely identifying a data item, and it can be either a primary key or a foreign key. A primary key is a key that uniquely identifies a data item within a table, while a foreign key is a key that uniquely identifies a data item in another table.A relational data model is a database model based on the first-order predicate logic. Its core idea is to describe a database as a collection of predicates over a finite set of predicate variables, describing constraints on the possible values and combinations of values that can occur in instance relations. In contrast to other data models, like the hierarchical and network models, the relational model achieves simplicity by applying certain rules, called normal forms, which define when a relation is considered "well structured". The most prominent normal form is the third normal form (3NF), which enforces that no non-trivial functional dependencies exist between any non-key attribute and any proper subset of any key.A relational data model is a database model based on the relational approach of data management. In such a model, data is organized into tables, and each table represents a single entity or concept. Tables are linked together by means of foreign keys, which are attributes that can be used to identify a row in one table that corresponds to a row in another table.The relational data model has several advantages over other database models:- It is easy to understand and use.- It is easy to extend and modify.- It supports integrity and security.- It is efficient and scalable.A relational data model is a database model based on the first-order predicate logic. In this model, data is represented in the form of tuples (rows) and attributes (columns). The main advantage of the relational model is its simplicity and ease of use. It is also easy to extend and modify the data in a relational database. However, the relational model has some limitations, such as its inability to represent certain types of relationships between data.