International parity conditions: Relative purchasing power parity, interest rate parity, Domestic Fisher effect, International Fisher effect. Though to some extent the above theories provide logical explanation for the fluctuations in exchange rates, yet these theories falter as they are based on challengeable assumptions [e.g., free flow of goods, services and capital] which seldom hold true in the real world.
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.
These cover the bulk of countries outside Europe. Forex brokers catering for India, Hong Kong, Qatar etc are likely to have regulation in one of the above, rather than every country they support. Some brands are regulated across the globe (one is even regulated in 5 continents). Some bodies issue licenses, and others have a register of legal firms.
The modern foreign exchange market began forming during the 1970s. This followed three decades of government restrictions on foreign exchange transactions under the Bretton Woods system of monetary management, which set out the rules for commercial and financial relations among the world's major industrial states after World War II. Countries gradually switched to floating exchange rates from the previous exchange rate regime, which remained fixed per the Bretton Woods system.
The foreign exchange market is unique for several reasons, mainly because of its size. Trading volume in the forex market is generally very large. As an example, trading in foreign exchange markets averaged $5.1 trillion per day in April 2016, according to the Bank for International Settlements, which is owned by 60 central banks and is used to work in monetary and financial responsibility. 
Believe it or not, this question does come up from time to time, especially from anyone unfamiliar with the foreign exchange market. Unlike the futures markets, there is no central governing body nor any arbitration panels or clearing houses that control the foreign exchange market. All trade is conducted through credit agreements between individual members.

Because the functionality of the trading platform has such a huge impact on your experience trading forex, take the time to try before you buy. Explore the features of your top two or three brokerages, either by diving deeply into their site’s introductory info or by running a demo of their platforms. The platform that’s best for you will feel intuitive and clear: You shouldn’t have to scour the site to find basic functions.
In 1876, something called the gold exchange standard was implemented. Basically it said that all paper currency had to be backed by solid gold; the idea here was to stabilize world currencies by pegging them to the price of gold. It was a good idea in theory, but in reality it created boom-bust patterns which ultimately led to the demise of the gold standard.
Currency rates are representative of the Bloomberg Generic Composite rate (BGN), a representation based on indicative rates only contributed by market participants. The data is NOT based on any actual market trades. Currency data is 5 minutes delayed, provided for information purposes only and not intended for trading; Bloomberg does not guarantee the accuracy of the data. See full details and disclaimer.
Alongside choosing a broker, you will also be researching the Forex trading software and platforms they offer. The trading platform is the central element of your trading, and your main working tool. It is an essential piece of the puzzle, as the best Forex tools can have a significant impact on your trading results. So, what should you be looking for when considering your options?

One of the most unique features of the forex market is that it is comprised of a global network of financial centers that transact 24 hours a day, closing only on the weekends. As one major forex hub closes, another hub in a different part of the world remains open for business. This increases the liquidity available in currency markets, which adds to its appeal as the largest asset class available to investors.
Hedge funds – Somewhere around 70 to 90% of all foreign exchange transactions are speculative in nature. This means, the person or institutions that bought or sold the currency has no plan of actually taking delivery of the currency; instead, the transaction was executed with sole intention of speculating on the price movement of that particular currency. Retail speculators (you and I) are small cheese compared to the big hedge funds that control and speculate with billions of dollars of equity each day in the currency markets.
Just like stocks, you can trade currency based on what you think its value is (or where it's headed). But the big difference with forex is that you can trade up or down just as easily. If you think a currency will increase in value, you can buy it. If you think it will decrease, you can sell it. With a market this large, finding a buyer when you're selling and a seller when you're buying is much easier than in in other markets. Maybe you hear on the news that China is devaluing its currency to draw more foreign business into its country. If you think that trend will continue, you could make a forex trade by selling the Chinese currency against another currency, say, the US dollar. The more the Chinese currency devalues against the US dollar, the higher your profits. If the Chinese currency increases in value while you have your sell position open, then your losses increase and you want to get out of the trade.
Forex brokers provide leverage up to 50:1 (more in some countries). For this example, assume the trader is using 30:1 leverage, as usually that is more than enough leverage for forex day traders. Since the trader has $5,000, and leverage is 30:1, the trader is able to take positions worth up to $150,000. Risk is still based on the original $5,000; this keeps the risk limited to a small portion of the deposited capital.

Unlike a stock market, the foreign exchange market is divided into levels of access. At the top is the interbank foreign exchange market, which is made up of the largest commercial banks and securities dealers. Within the interbank market, spreads, which are the difference between the bid and ask prices, are razor sharp and not known to players outside the inner circle. The difference between the bid and ask prices widens (for example from 0 to 1 pip to 1–2 pips for currencies such as the EUR) as you go down the levels of access. This is due to volume. If a trader can guarantee large numbers of transactions for large amounts, they can demand a smaller difference between the bid and ask price, which is referred to as a better spread. The levels of access that make up the foreign exchange market are determined by the size of the "line" (the amount of money with which they are trading). The top-tier interbank market accounts for 51% of all transactions.[60] From there, smaller banks, followed by large multi-national corporations (which need to hedge risk and pay employees in different countries), large hedge funds, and even some of the retail market makers. According to Galati and Melvin, “Pension funds, insurance companies, mutual funds, and other institutional investors have played an increasingly important role in financial markets in general, and in FX markets in particular, since the early 2000s.” (2004) In addition, he notes, “Hedge funds have grown markedly over the 2001–2004 period in terms of both number and overall size”.[61] Central banks also participate in the foreign exchange market to align currencies to their economic needs.
The foreign exchange market is an over-the-counter (OTC) marketplace that determines the exchange rate for global currencies. Participants are able to buy, sell, exchange and speculate on currencies. Foreign exchange markets are made up of banks, forex dealers, commercial companies, central banks, investment management firms, hedge funds, retail forex dealers and investors.
Unlike stock markets, which can trace their roots back centuries, the forex market as we understand it today is a truly new market. Of course, in its most basic sense - that of people converting one currency to another for financial advantage - forex has been around since nations began minting currencies. But the modern forex markets are a modern invention. After the accord at Bretton Woods in 1971, more major currencies were allowed to float freely against one another. The values of individual currencies vary, which has given rise to the need for foreign exchange services and trading.