ITM means in the money. A call is ITM when the underlying price is above its strike; a put is ITM when the underlying price is below its strike.
With a stock at $55, a $50 call has $5 of intrinsic value per share. With the stock at $45, a $50 put has $5 of intrinsic value per share. Before expiration, the option's market price can also include time value.
ITM does not necessarily mean the trade is profitable. A $50 call bought for $8 and worth $5 at expiration still loses $3 per share before costs. See moneyness and profitability, in-the-money options, ATM and OTM.
