What does vertical scaling refer to?

Vertical scaling, also known as "scaling up," involves increasing the capacity of a single server or instance by adding more resources, such as CPU, RAM, or storage. In the context of MuleSoft and the management of Mule applications, resizing a worker's vCore size is a direct example of vertical scaling. By adjusting the vCore size, you enhance the processing power available to that particular instance, allowing it to handle more significant workloads or more complex processes.

This approach contrasts with horizontal scaling, where the focus is on adding more instances to distribute load rather than increasing the resources of a single instance. Therefore, by increasing the vCore size, you're effectively improving the performance and capability of that specific worker without the need to deploy additional instances.