A distributed application operates across multiple computers connected via a network, contrasting with standalone applications that run on a single system. They can range from simple client-server models to complex systems involving microservices in a cloud-native environment. Unlike standalone applications, distributed ones offer advantages like scalability, reliability, and faster response times due to their ability to run on multiple systems simultaneously. They support various architectures, including client-server, peer-to-peer, and microservices, enabling diverse applications like web browsers, e-commerce sites, and cloud platforms. However, the complexity of design, potential security risks, and increased operational overhead are notable challenges. Tools such as Docker and Kubernetes are commonly used for deploying and managing distributed applications, leveraging cloud platforms like AWS and Microsoft Azure for scalability and resource sharing. Understanding the intricacies of these systems is crucial for developers aiming to implement effective distributed applications.