ELI5: Explain Like I'm 5

Wall-clock time

Wall-clock time is basically the time that you see on the clock hanging on your wall or on your watch. When you ask someone what time it is, they will probably tell you the wall-clock time.

But, when we talk about wall-clock time in a different context, like in computing, it means the actual time that passes while a computer program is running. When you run a program on your computer, it takes a certain amount of time for it to complete all of its tasks. That amount of time is the wall-clock time.

For example, let's say you have a program that needs to sort a million numbers. It might take a few seconds or even minutes to complete, depending on how fast your computer is and how efficient the program is. The time it takes for the program to complete is the wall-clock time.

Wall-clock time is different from other types of time measurements because it takes into account all of the time that passes, including any time that the program is waiting for something else to happen, like waiting for input from the user or waiting for data to be loaded from a disk.

So, in summary, wall-clock time is the actual time that passes while a program is running and it takes into account all of the delays and waiting periods that may occur.