K/M/G/T/P = decimal prefixes. K is 1000. M is 1,000,000. etc.
Ki/Mi/Gi/Ti/Pi = binary prefixes. Ki is 2¹⁰ (1024), Mi is 2²⁰ (1,048,576), etc.
It’s a disambiguation of the previous system where we would use KB to interchangeably mean 1000 or 1024 depending on context.
Computers have ruled the planet for longer than the Greeks ever did. The history lesson is appreciated, but we’re living in the future, now, and the future is digital.