MT4 demo (volume rather than units?)

when placing an order on the new MT4 on oanda…instead of units to trade, it asks for volume…on the FXpractice it is 1000, 100,000, 500,000…and so on

can someone please explain this and breakdown volume to units?

am I totally off base here?..is there an option to type in units rather than volume?

it just seems more complicated than units, and Im guessing there must be an option for units on the ‘place order’ pop-up…

Ive been looking at the MT4 demo and trying to figure out how to place trades…its seems very complicated compared to the FX practice trade on oanda…

is there any way to use MT4 but still place my trades on the FX practice trade platform?

Im confused…is there an MT4 tutorial? plus I dont like how MT4 shows the currency pairs (bid/ask)…the FX practice trade shows them in ‘blocks’ and seems much more straight-forward to me…