Microservices are a software development technique - a variant of the Service Oriented Architecture (SOA) structural style - that arranges an application as a collection of loosely coupled services
Microservices - also known as the microservice architecture - is an architectural style that structures an application as a collection of services that are
The microservice architecture enables the rapid, frequent and reliable delivery of large, complex applications. It also enables an organization to evolve its technology stack.
Source: microservices.io
In software engineering, a microservice architecture is an architectural pattern that arranges an application as a collection of loosely coupled, fine-grained services, communicating through lightweight protocols. One of its goals is to enable teams to develop and deploy their services independently. This is achieved by reducing several dependencies in the codebase, allowing developers to evolve their services with limited restrictions, and hiding additional complexity from users. Consequently, organizations can develop software with rapid growth and scalability, as well as use off-the-shelf services more easily. Communication requirements are reduced. These benefits come with the cost of maintaining decoupling, so a microservice architecture may be suitable only if the application is too complex to manage as a monolith. Interfaces need to be designed carefully and treated as public API. One technique used is having multiple interfaces on the same service or multiple versions of the same service to avoid disrupting existing users of the code.
A microservice is analogous to bounded context in domain-driven design.