At the present time, there is a remarkable trend for application modularization that splits the large hard-to-change monolith into a focused microservices cloud-native architecture. The monolith keeps much of the state in memory and replicates between the instances, which makes them hard to split and scale. Scaling up can be expensive and scaling out requires replicating the state and the entire application, rather than the parts that need to be replicated.
In comparison to microservices, which provide separation of the logic from the state, the separation enables the application to be broken apart into a number of smaller more manageable units, making them easier to scale. Therefore, a microservices environment consists of multiple services communicating with each other. All the communication between services is initiated and carried out with network calls, and services exposed via application programming interfaces (APIs). Each service comes with its own purpose that serves a unique business value.