Doubt in emma's paint project

Question

i couldn't understand what is e in the handle move function and what is evt in handlestart function in the js section of code.i also couldn't get how exactly is the handlestart function working?can anyone please explain it.Thanks.
https://code.sololearn.com/W6d0E0j5wCMB/?ref=app

Answer 1

not sure what you mean exactly by system defined keyword

but in this case the first parameter that is passed to the event handler is an event object

call it king_kamehameha_the_first if you want

Answer 2

evt and e are the same thing, and it's a better practice to keep the names consistent, unlike in here

both are event object, and they allow to "convert" user interactions into logic (such as drawing a line)

https://www.w3schools.com/js/js_events.asp

Answer 3

@Burey so that means evt and e are system defined keywords