Final answer:
The law you are referring to is Amdahl's Law, which states that the overall improvement in system performance when only one component is improved is limited by how much that component is used. This principle plays a critical role in computer system design and how end-users experience the computer's operations.
Step-by-step explanation:
When designing a computer system, focusing on improving just one part without modifying others will eventually hit a point of diminishing returns. This concept is related to Amdahl's Law, which is particularly relevant in the context of improving system performance. Amdahl's Law states that the overall system performance improvement gained by enhancing a particular component is limited by the fraction of time that the improved component is actually used. For instance, if you upgrade the processor in a computer but do not upgrade the memory or storage, the system will only perform significantly better in tasks that are CPU-intensive and not bottlenecked by memory or disk speed.
At the physical level, an engineer would understand this as optimizing the electronic changes flowing through the computer hardware. On the design level, a programmer might consider how the system architecture should accommodate efficient code execution. Meanwhile, at the commonsense level, a user experiences the end result of these improvements when the computer performs tasks such as word processing or solving equations more rapidly.