and for the record "i" could be anything you choose to call it, its just the name of a local variable to the loop(and you can use it inside the loop as well)
I just use i as the variable name as shorthand for iteration, which of course means
Iteration means the act of repeating a process usually with the aim of approaching a desired goal or target or result.
unless I have a specific meaning for that variable
maybe this will help you see
void setup()
{
Serial.begin(9600);
}
void loop()
{
for(int counter = 0; counter < 10; counter++)
{
Serial.println(counter);
delay(1000);
}
}
which should count from 0-9 then reset and loop again (since its in the main loop)