Unrealized p/l

I am using dealbook 360. I understand that unrealized p/l probably means unrealized profit/loss… but what does this number represent? If it says i have 10,000 cash and my unrealized p/l is -2000, does this mean I acutally only have 8,000 left?

Or… is unrealized p/l the cumulative amount of how much ive gained or lost?

Pretty much. If you have $10,000 cash in your account and your unrealized P/L says -$2,000, this means you still have positions open. If you were to close all your positions at that very moment, you would then [I]realize[/I] a loss of $2,000 bringing your account balance down to $8,000.

The unrealized p/l ties in with your available margin. For example, if you have a $10,000 account and put on a position that required $1000 in margin, you would have $9000 left in available margin (for taking on further positions or buffering against losses). If you then experienced $2000 in unrealized losses on your open trade, your available margin would drop down to $7000. If your unrealized losses ran high enough to drop your available margin below the margin required for your position you would either get a margin call or experience a forced liquidation (depending on your broker).