An Enter / Exit Close operator allows you to enter on the close of the bar that triggers an entry or exit condition.
On entering a trade, in most cases, your entry conditions are met and you enter on the open of the next bar. The Enter / Exit Close operator will allow you to enter on the close of the entry bar that meets all of your entry conditions. Please note that in real trading, this is rarely possible, so be sure to add slippage when you historically test your system.
On exiting a trade, this operator will also allow you to exit on the close bar of the trade, providing that no other operator has exited the trade. For example, let’s say that you want to exit on the close of a Gap Up and you also have an Enter / Exit Close operator. Once the gap up is complete, the Enter / Exit Close operator will exit you on the close of the Gap Up (rather than on the open of the next bar), unless your Hard Stop has been previously hit. (Note that in most cases, some other indicator will stop you out of your trade.)