What does "vertical scaling" in cloud computing refer to?

Vertical scaling, also known as "scaling up," in cloud computing refers to increasing the capacity of existing resources. This involves enhancing the power of a single server or resource by adding more CPU, RAM, or storage. Vertical scaling allows applications to handle increased loads on a single instance, making it easier to manage and potentially improving performance without the need to distribute workloads across multiple machines.

The ability to scale vertically is crucial for applications that require higher performance but are designed to run on a single instance. This contrasts with horizontal scaling, where additional instances or servers are added to distribute the load, which is not the case here. Understanding vertical scaling is key when considering how to optimize resource usage and can be particularly useful for database management systems or applications that keep state.

In contrast, the other options describe different concepts within cloud management or scaling strategies. Adding more instances of servers pertains to horizontal scaling, while decreasing the number of resources relates to scaling down or optimizing resource usage. Switching to a different cloud service provider involves migrating services rather than altering the existing resources. Thus, the emphasis on increasing capacity with existing resources solidifies the definition of vertical scaling.