Microservices architecture is a software development approach that organizes applications as a collection of independent, loosely coupled services, each tasked with a single business function, and communicating via APIs. This method offers a flexible and scalable alternative to traditional monolithic architectures, which are unified and interdependent, by allowing individual components to be updated and scaled independently. Popularized by companies like Netflix and Amazon in the early 2010s, microservices align well with cloud computing and agile methodologies, providing benefits in scalability, flexibility, and maintenance. However, they also introduce challenges such as increased complexity and monitoring requirements, making them more suitable for large-scale applications. Effective design and testing strategies, such as domain-driven design and integration testing, along with technologies like Docker, Kubernetes, and CI/CD tools, are crucial for successful microservices implementation. Despite the challenges, microservices offer clear advantages in modularity, independence, and decentralized data management, making them an attractive option for organizations seeking agile and robust software solutions.