DBMS ARCHITECTURE

The overall architecture of a DBMS defines how users interact with the database. Logically, it is categorized into one of three main types: 1-tier, 2-tier, and 3-tier architecture. 

1. 1-Tier Architecture

In this architecture, the database is directly accessible to the user. There is no intermediate layer or security abstraction. This model is mainly used in development environments where programmers interact directly with the DBMS.  

2. 2-Tier Architecture

This involves a client-server model. The client (which contains the user interface and application logic) interacts directly with the server (which hosts the DBMS) to process queries. This is common for small networks, like desktop applications interacting with remote databases.  

3. 3-Tier Architecture

This is the most common architecture for large-scale applications and includes an additional layer called the application server (middleware). This layer separates the client, application logic, and database.  

It improves scalability, security, and maintenance.  

It is common in web-based applications, where the client (browser) communicates with a web server (application server), which then interacts with the database server.