Microservices are an architectural style for developing software applications as a collection of small, independent, and loosely-coupled services. Each microservice is responsible for a specific business function or capability, and communicates with other services through APIs (Application Programming Interfaces).

The idea behind microservices is to break down a complex monolithic application into smaller, more manageable services that can be developed, deployed, and scaled independently. This makes it easier to update and maintain the application, and enables more agile and efficient development processes.

Microservices typically have the following characteristics:

  1. Small size: Each microservice is small in size and has a single responsibility.
  2. Independent: Microservices are independently deployable and scalable.
  3. Loosely-coupled: Microservices communicate with each other through APIs, and are not tightly coupled.
  4. Resilient: Microservices are designed to be fault-tolerant and resilient.
  5. Agile development: Microservices enable agile development processes, as each service can be developed and deployed independently.

Some popular technologies and tools used for building and managing microservices include Docker, Kubernetes, and service meshes like Istio and Linkerd.