Answer
Forex trading is the buying and selling of currencies. Investopedia had a good definition (and video!) Here:

http://www.investopedia.com/terms/f/forex.asp#axzz25QAKIlz9

The differences between Forex and Futures?

Answer
Hypersignal is pretty confused:

a) Forex more liquid than futures
Hmm, well I am sure that the retail forex sites that he trades tells him this, but the $4T figure that he mentions is a different market than the one he is trading. That's the Interbank market that he doesn't have access to. You can trade Forex with significantly smaller spreads in futures markets than you can in retail forex markets.

b) Futures is only open 7 hours per day
No - Pit trading is only open 7 hours per day. Electronic futures markets are open almost all week beginning on Sunday afternoon and ending Friday evening. There is no pit trading in Hypersignal's forex market so it's not at all clear why he would sya futures trading is only open when there is pit trading but electronic trading doesn't count. By his definition, his forex market is never open.

c) You pay commissions trading futures contracts
Well - let's see suppose you pay $10 a rounfd turn on a Euro contract for $125,000 worth of Euros. That's a 0.008% loss. There are plenty of YA morons buying physical silver that take 25% transaction fee losses. The 0.008% loss is nothing compared to the larger spreads Hypersignal pays.

d) "Forex is the market I prefer"
I've got $1000 that says Hypersignal has never had a position in a futures contract.