What are the main approaches to dividing a monolithic application into components?

Main approaches to dividing a monolithic application into components:

1. Functional separation — highlighting components based on business functions (e.g., payment module, user management module).
2. Layered separation — dividing into layers such as presentation, business logic, data access.
3. Modular separation — highlighting independent modules with clearly defined interfaces.
4. Using microservice architecture — splitting into separate services that interact via APIs.

Example: in an online store, components can be distinguished for product catalog, cart, checkout, and payment, each implemented as a separate module or service.