Forex is always traded in pairs – for example AUD/USD. You speculate on whether the price of one country's currency will rise or fall against the currency of another country, and take a position accordingly. Looking at the AUD/USD currency pair, the first currency (AUD) is called the 'base currency' and the second currency (USD) is known as the 'counter currency'. 
Currency markets are important to a broad range of participants, from banks, brokers, hedge funds and investor traders who trade FX. Any company that operates or has customers overseas will need to trade currency. Central banks can also be active in currency markets, as they seek to keep the currency they are responsible for trading within a specific range.
The Germany 30 chart above depicts an approximate two year head and shoulders pattern, which aligns with a probable fall below the neckline (horizontal red line) subsequent to the right-hand shoulder. In this selected example, the downward fall of the Germany 30 played out as planned technically as well as fundamentally. Towards the end of 2018, Germany went through a technical recession along with the US/China trade war hurting the automotive industry. Brexit negotiations did not help matters as the possibility of the UK leaving the EU would most likely negatively impact the German economy as well. In this case, understanding technical patterns as well as having strong fundamental foundations allowed for combining technical and fundamental analysis to structure a strong trade idea.
Trading foreign exchange on margin carries a high level of risk and may not be suitable for all investors. The high degree of leverage can work against you as well as for you. Before deciding to trade foreign exchange you should carefully consider your investment objectives, level of experience and risk appetite. The possibility exists that you could sustain a loss of some or all of your initial investment and therefore you should not invest money that you cannot afford to lose. You should be aware of all the risks associated with foreign exchange trading and seek advice from an independent financial advisor if you have any doubts.