Being an architectural style, microservices, or microservice architecture, carry out structuring a solution as a collection of services that are tightly coupled. This architecture also facilitates the delivery and Continuous Deployment (CD) of large, complex applications. If any organization wants to evolve its technology stack, microservices help in achieving that.
Microservice architecture is not going to solve all the problems of the world. In fact, like everything, it has several disadvantages, complexities, and problems. When using this architecture, numerous problems emerge and, of course, you must solve them all.
In addition, it is necessary to change paradigms to define and create microservices, and that does not involve simply breaking a large solution into smaller pieces.
In summary, the microservice architecture style is an approach that creates a single application organized by a suite of small services. Another interesting aspect is that each service could run independently, meaning that there are no restrictions on the technology. As mentioned before, these services are built based on business capabilities.
Another important piece of information is that they should work through fully automated and independent deployment mechanisms, which means that if one microservice breaks, the other ones should still go to production if they are green.
The first time this term appeared was on Martin Fowler's website (https://martinfowler.com/articles/microservices.html). Here is a visual representation:
