I think indicators are tools that are used in technical analysis. These tools are based on statistical information that are taken from the history of a pair. Most of the indicators have very little difference. Almost all the indicators are depending on past history of currency pair prices. My favorite indicator is Boilinger band indicator. indicator is someone's trading strategy which is programmed and formulated. the message is from chart directly but convert to another way to look. we can use indicator but we can not get all his thoughts about trading. so, it help you to understand trading signal. but you should have own judgement to deal the signal