Close Vs Last

What is the difference between close vs last in scripting?

I get vastly different results when using these on daily backtests. I thought they would be the same value.

My understanding is that every bar on a chart has a Close price which is the last price of that bar, but only the final, current bar on the right hand edge has the Last price. That is, the close price of the last bar is LAST.

see https://help.optuma.com/kb/faq.php?id=1091

cheers
Michael Colantoni