Data models in Database Management Systems (DBMS) serve as conceptual frameworks for organizing and representing data. They define the structure, relationships, and constraints of data stored in databases. Common types of data models include:

1. Relational Model: Organizes data into tables with rows and columns, facilitating efficient querying and manipulation. Widely used in SQL-based databases like MySQL and PostgreSQL.

2. Hierarchical Model: Represents data in a tree-like structure with parent-child relationships. Mainly used in older systems like IMS (Information Management System).

3. Network Model: Extends the hierarchical model by allowing multiple parent-child relationships, enhancing flexibility but increasing complexity.

4. Object-oriented Model: Represents data as objects with properties and methods, suitable for modeling complex data structures and relationships.

Data models are significant as they provide a standardized way to describe and understand data, enabling effective communication between stakeholders during database design and development. They also ensure data integrity, consistency, and interoperability across different systems and applications.

Applications of data models include database design, data integration, data migration, and system development. By adhering to a specific data model, organizations can streamline data management processes, improve data quality, and enhance decision-making capabilities. Additionally, data models serve as the foundation for implementing database systems, enabling efficient storage, retrieval, and manipulation of data to meet business needs.