Explain the concept of vertical scaling in systems, and in what situations it is applied?

Vertical scaling is the process of increasing the capacity of a single server or system node by adding resources such as processors, RAM, disk space, etc.

It is used when:

• You need to improve the performance of an existing server without changing the application architecture.
• The system is not designed for distributed operation or is difficult to scale horizontally.
• A quick performance boost is required without implementing complex clustering solutions.

For example, if you have a database on a single server and the load is increasing, you can increase the number of CPU cores and memory to speed up query processing.

Disadvantages of vertical scaling:

• There is a physical limit to the resources of a single server.
• The cost of powerful equipment can be high.

Unlike horizontal scaling (adding new servers), vertical scaling is easier to implement but less flexible under heavy loads.