A forex signal is a suggestion for entering a trade on a currency pair, usually at a specific price and time.
Due to the timely nature of signals, they are usually communicated via email, website, SMS, RSS, tweet or other relatively immediate method.
As forex is popularly touted as a get-rich-quick method there are a number of services that supply signals of debatable quality, which do not answer the users' expectations for profits.
Technical analysis, such as ichimoku and candlestick charting, show both short and long term price trends giving the signal provider flexibility in supplying a range of trade options.
Price action gives extremely short term trade ideas, often more suited to scalping.