What is the role and purpose of a repository in software system architecture?

A repository in software architecture serves as an abstraction for data access. Its main role is to separate application logic from the details of data storage and retrieval.

Purpose of the repository:

• Encapsulation of operations with data sources (databases, networks, file systems).
• Providing a convenient interface for retrieving, saving, and updating data.
• Ensuring a single point of access to data, which simplifies testing and maintenance.
• Hiding implementation details (e.g., SQL queries) from business logic.

Example: in an Android application, a repository can fetch data from a local Room database and/or from a remote API, providing the ViewModel with a unified data stream without needing to know where the data came from.