When trading forex, you always speculate on whether the price of the base currency will rise or fall against the counter currency. So in AUD/USD if you think AUD will rise against USD, you go long (buy) the currency pair. Alternatively, if you think AUD will fall against USD (or that USD will rise against AUD), you go short (sell) the currency pair.
When it comes to price patterns, the most important concepts include ones such as support and resistance. Put simply, these terms represent the tendency of a market to bounce back from previous lows and highs. Support is the market's tendency to rise from a previously established low. Resistance is the market's tendency to fall from a previously established high. This occurs because market participants tend to judge subsequent prices against recent highs and lows.
If traders are positive on the prospects for the Yen, they would expect the number on the right to go down – i.e. the Yen would be getting stronger against the Dollar. Traders would be buying less Yen with a Dollar as the Yen got stronger. Similarly, if the Yen was expected to weaken, forex traders would expect the Yen number to go up, reflecting the fact that the dollar could buy more yen.