Below you will find definitions to some common account balance terms:
Balance: Your balance is your deposits minus your withdrawals plus the profit & loss of previous positions. Your balance does not include the P&L of the current open positions.
Available Balance: This is the amount available to be used for trading. It is your current balance plus the P&L of your current open positions minus initial margins.
P&L: This is the profit and loss for all open positions (Profit + Loss + Daily premium * number of days).
Equity: This is the current account valuation. It is your balance + any unrealized P&L.