In modern distributed systems and cloud computing architectures, high availability and high scalability are core requirements to ensure the continuous and stable operation of services. As key technologies for achieving these two goals, high-availability clusters and load-balancing clusters have significant differences in their design concepts and application scenarios, while also maintaining close connections. This paper aims to conduct an in-depth analysis of the core objectives, working principles, technical advantages and disadvantages, and typical application cases of high-availability clusters and load-balancing clusters. By introducing an analogical model of a “restaurant kitchen,” the differences between the two are intuitively explained, and their technical characteristics are compared in detail. Additionally, a detailed practical case is included to specifically demonstrate the collaborative work of high-availability and load-balancing technologies through the construction process of Keepalived and HAProxy. Finally, taking the architecture of a typical e-commerce website as an example, this paper demonstrates the best practice of organically combining the two cluster technologies in a production environment to build a robust and high-performance distributed system. Research shows that understanding the differences between the two and implementing collaborative deployment is the cornerstone of designing modern IT infrastructure.