A software design pattern known as monolithic architecture calls for the creation of a whole, self-contained program. In this architecture, the application's components are all closely connected and are each delivered as a separate executable file.
The application is created as a single entity in a monolithic architecture, sharing the same resources and memory. It might be challenging to maintain and update the codebase because it is frequently huge and complex. It can be run on a single system or a group of machines and is simple to deploy.

Small- to medium-sized programs that have straightforward functionality and don't need a lot of scalability or modularity frequently employ monolithic architecture. However, as the application's complexity and scale increase, it becomes more challenging to administer and maintain, which can result in extended development times, expensive expenditures, and constrained scalability.

The monolithic design has lost favor as microservices architecture has grown in prominence because it restricts the ability to scale, update, and modify individual components of the program. Nevertheless, a monolithic design is still used by many legacy systems and applications.
A software design pattern known as monolithic architecture calls for the creation of a whole, self-contained program. There are three main layers in this architecture:

Presentation layer:

The user interface and user interactions are handled by this layer. It includes all the aspects that the user may see, such as graphical elements, web pages, and forms. Through APIs and other interfaces, the presentation layer connects with the other application layers.

Application layer:

The application's business logic is contained in this layer. It covers every element that helps the application's functionality run well, including data processing, workflows, and algorithms. To access and modify the data, the application layer interacts with the data layer.

Data Access layer:

The management of data storage and retrieval falls under the purview of this layer. Data access objects, data models, and data connectors are just a few examples of the components that interact with the database.

All these layers are closely connected and deployed as a single executable file in a monolithic architecture. There are benefits
and drawbacks to this strategy.

Advantages Of Monolithic Architecture:

1. As there is only one codebase to handle, development and deployment are simplified.
2. Since all components are merged into a single unit, testing and debugging are straightforward.
3. Low latency because every component is on the same server.

Disadvantages:

1. Maintenance is challenging because any update necessitates rebuilding and redeploying the entire application.
2. Limited scaling since the whole application must be scaled at once.
3. Updating is dangerous since even small changes might have a big effect on the whole application.
4. Monolithic architecture, despite its drawbacks, is nevertheless employed in some situations, such as small- to medium-sized systems with restricted functionality or applications that don't need a lot of scalability or modularity. However, microservices architecture has become a more preferred solution as applications grow in complexity and size.