A forward is a spot rate adjusted for the interest earned or paid on each currency between now and the value-date. Nothing changes hands until then, apart from collateral in some arrangements. The adjustment, quoted in forward-points, is arithmetic rather than a forecast.
Forwards are the workhorse of corporate currency-hedging. A manufacturer with a known euro cost in six months removes the exchange rate from its planning by fixing it today.
Example: spot EUR/USD 1.0840, six-month forward points plus 110, so the outright rate is 1.0950. An importer locks EUR 2,000,000 at that rate and knows it will pay $2,190,000 in six months regardless of where spot goes.
Related: forward-points, outright-forward, interest-rate-parity