4. Microservices

The "Microservices" architectural style is an approach that enables a single application to be developed as a suite of small services, each running in its own process and communicating with lightweight mechanisms, often an HTTP REST resource API. These services are built around business capabilities and can be deployed independently by fully automated machines. There is a minimum of centralized management of these services, which can be written in different programming languages and use different data storage technologies.

(Martin Fowler and James Levis, "Microservices", March 2014 .)