Microservices architecture is an approach to building applications as a collection of small, independent services that communicate over APIs. Unlike monolithic applications—where everything is built as a single unit—microservices allow each feature or function to be developed, deployed, and scaled independently.

Core characteristics of microservices:

• Each service is focused on a single business capability.
• Services are loosely coupled and independently deployable.
• Communication typically happens through lightweight protocols like HTTP/REST or messaging queues (e.g., RabbitMQ, Kafka).
• Teams can work on different services in parallel using different tech stacks.

Advantages:

• Scalability: Individual services can be scaled based on demand.
• Fault isolation: If one service fails, it doesn’t bring down the entire application.
• Faster development: Smaller teams can work on different services simultaneously.
• Technology flexibility: Each service can use its own programming language or database.

Challenges:

• Increased complexity in managing and deploying services.
• Requires robust DevOps practices (CI/CD, monitoring, logging).
• Needs API gateway and service discovery mechanisms.

Popular tools in microservices include Docker, Kubernetes, Spring Boot, and Istio. For beginners, understanding microservices is key to working in modern, scalable cloud-native environments.