Forex markets use the same expressions and rules of selling
and buying as other financial markets. Currency trading involves
buying and selling, so being understanding these terms is
necessary.
Long
Long position means same in all the financial markets.
If you buy a stock or currencies you are hoping for prices to
move higher. In forex you bought currency piar. You are looking
to sell currency pair at a higher price. To get you money from
the market you have to sell stock or currency pair.
Short
A short position means that you sold stock or currency pair
that you havent owned. When you sell short a stock, it means
you have to borrow the stock from your broker. Of course you
have to pay fee to you broker. In forex market it means you sold
a curreny pair. When you sell currency pair, you are hoping
for currency pair to move lower in price to make money. If you add
short positions at different price leves you are adding to your
short position.
Cash
If you dont have any positions you are in cash. Sometimes this
is the best technique to avoid volatile markets or markets are in
trendless enviroment.