A netting account combines all trades on the same instrument into a single position.
If you place a trade in the opposite direction, it will reduce, close, or reverse your existing position instead of opening a separate position.
For example, if you have a Buy position of 500 units and then place a Sell order of 200 units, your remaining position will be a Buy of 300 units.
This makes it easier to manage your overall exposure on each instrument.