The essence of life is statistical improbability on a colossal scale.
You’ve probably experienced software that works well with a small amount of data but gets slower and slower as more data is added. Some systems get a little slower with more data. With others, the slow-down is much bigger, often dramatically so.
When discussing scalability, there is terminology that describes this phenomenon. This enables us to communicate with each other with great specificity.
This appendix describes some basic terminology, a more mathematical way of describing the same concepts, and finally some caveats for how modern systems do or do not act as one would expect.