What is a 'protocol upgrade'?
What does  'general software maintenance' mean, and why is this needed?
What is the difference? 

Can someone use a metaphor or use child language to explain this to me and any other feeling ignorant on this subject? 
And please assume that all I know about computers is how to turn them on & off. 

#asknostr #bitcoin #protocol #OG #developers #devs #generalsoftwaremaintenance #bitcoinsoftware #core #node