In the money
A call whose strike is below the underlying price, or a put whose strike is above it. An in-the-money option has intrinsic value.
Moneyness describes where the strike sits relative to the current price of the underlying. An in-the-money option would be worth something if exercised now, and that amount is its intrinsic value.
Deep in-the-money options behave much like the underlying itself, with deltas close to 1 for calls or -1 for puts, and they cost more because they carry more intrinsic value. Options that are in the money at expiration by at least $0.01 are generally exercised automatically.
Illustrative example (hypothetical numbers, not a real trade): with a stock at $80, a $70 call is $10 in the money and a $90 put is $10 in the money. If the $70 call trades at $11.50, $10.00 of that price is intrinsic value and $1.50 is extrinsic value.