More specifically, the spot market is where currencies are bought and sold according to the current price. That price, determined by supply and demand, is a reflection of many things, including current interest rates, economic performance, sentiment towards ongoing political situations (both locally and internationally), as well as the perception of the future performance of one currency against another. When a deal is finalized, this is known as a "spot deal". It is a bilateral transaction by which one party delivers an agreed-upon currency amount to the counter party and receives a specified amount of another currency at the agreed-upon exchange rate value. After a position is closed, the settlement is in cash. Although the spot market is commonly known as one that deals with transactions in the present (rather than the future), these trades actually take two days for settlement.
The value of a country's currency depends on whether it is a "free float" or "fixed float". Free floating currencies are those whose relative value is determined by free market forces, such as supply / demand relationships. A fixed float is where a country's governing body sets its currency's relative value to other currencies, often by pegging it to some standard. Free floating currencies include the U.S. Dollar, Japanese Yen and British Pound, while examples of fixed floating currencies include the Chinese Yuan and the Indian Rupee.
An investor can profit from the difference between two interest rates in two different economies by buying the currency with the higher interest rate and shorting the currency with the lower interest rate. Prior to the 2008 financial crisis, it was very common to short the Japanese yen (JPY) and buy British pounds (GBP) because the interest rate differential was very large. This strategy is sometimes referred to as a "carry trade."
Traders who understand indicators such as Bollinger bands or MACD will be more than capable of setting up their own alerts. But for the time poor, a paid service might prove fruitful. You would of course, need enough time to actually place the trades, and you need to be confident in the supplier. It is unlikely that someone with a profitable signal strategy is willing to share it cheaply (or at all). Beware of any promises that seem too good to be true.
In every part of life, discipline is important, but neglecting discipline in day trading may potentially result in huge losses. Success without discipline is practically impossible. You need to be able to monitor prices for extended periods of time without making any rash trading decisions. This is hard and requires lots of discipline. Sometimes seeing profitable market moves that you have predicted but did not execute is painful, yet it is better to waste an opportunity, than to guarantee a loss.