What distinguishes horizontal scaling from vertical scaling in cloud computing?

Horizontal scaling refers to the process of adding more machines or instances within a system to distribute the workload and increase capacity. This approach allows for greater resilience and redundancy, as multiple machines can work in tandem to handle user requests or processes. It enables a system to scale out by accommodating more users or data without being dependent on the capabilities of a single machine.

In contrast, vertical scaling involves increasing the resources of a single machine, such as adding more CPU power or memory. While vertical scaling can boost the performance of that specific machine, it has its limitations in terms of maximum capacity and potentially higher downtime during upgrades.

The aspect of adding more machines to a pool is key to understanding how horizontal scaling operates. This method is particularly beneficial in cloud environments, where resources can be dynamically allocated, and it allows for improved load balancing and fault tolerance. Consequently, horizontal scaling is commonly utilized in cloud architectures to achieve high availability and better service performance.