What are Microservices

A microservice architecture builds one application as a set of small, independent services. Each service does one business job, runs in its own process, owns its own data, and talks to other services over the network (usually HTTP/JSON or messages).

• Small and focused: one service = one business capability (products, orders, payments...).
• Independently deployable: you can release the Order service without touching the Product service.
• Owns its data: each service has its own database; no other service reads its tables directly.
• Talks over the network: REST calls, gRPC, or events through Kafka/RabbitMQ.
• Owned by one team: the team that builds it also runs it ("you build it, you run it").

Instead of one big application, ShopEase becomes several small applications. The browser or mobile app talks to them (later through an API Gateway):

React / Android app
                   |
     +-------------+--------------+
     |             |              |
     v             v              v
+---------+  +-----------+  +-----------+
| Product |  |   Order   |  |   User    |
| Service |  |  Service  |  |  Service  |
|  :8081  |  |   :8082   |  |   :8083   |
+----+----+  +-----+-----+  +-----+-----+
     |             |              |
 product_db     order_db       user_db