Microservices are an architectural style where applications are composed of small, independent services that communicate using lightweight mechanisms like HTTP. Each service focuses on doing a small, well-defined job and is independently deployable. There is minimal centralized management of services, which may use different programming languages and data stores. While microservices provide benefits like flexibility, they also introduce challenges around performance, asynchronicity, failures, and complexity. Microservices represent an implementation choice governed by enterprise architecture principles, not dictated by EA. They differ from SOA in areas like synchronous vs. asynchronous communication and ceremony levels.