There are several major players when it comes to interpreting markets. There are economists, analysts, strategists, and traders. Traders are the most prevalent in this category; they are the ones who day trade for a living or dabble in the forex market here and there to make a few extra bucks. But even though they are the most populous, they affect the market the least.
Economists have quite a bit of influence over markets. These are government officials or collegiate professors who study the market for a living. When they make a proclamation, it carries a lot of weight. These individuals interpret the given data and then give their opinion of how they think markets will react. They are often incorrect, but they are right enough that their statements can influence the demand for a currency.
A strategist is more involved in the actual trading business. These people keep an eye out for where markets are headed, and then attempt to profit off of their observations. These individuals are great gauges for making future moves. If you are interested in futures markets or derivatives, these are good people to get information from.
An analyst studies the market conditions and then interprets them. There are two types of analysts: fundamental and technical. Fundamental analysts use broader market conditions such as economic and political data to make their decisions while technical analysts use charts and more complex mathematical data to try and spot trends and then move from there.