Linux Load Averages
Brenden Gregg does a deep dive into the history of Linux Load Averages.
https://www.brendangregg.com/blog/2017-08-08/linux-load-averages.html
They show an exponential 5 second moving average over the past 1 minute, 5 minutes and 15 minutes, of processes running on the CPU and ready to be run on the CPU, as well as processes which are in an uninterruptable wait state, which reflects processes waiting for other processes to do something. Together, these all give a user sensible number which roughly shows if load is increasing, decreasing or flat, and approximately how many CPU equivalents.
He does a bit of digging into the history of the Linux kernel, as this definition of Load Average is specific to Linux, and has been so for more than 20 years.