How to use an indicator?? (Indicator ko kaise use karte hain)

[bigearners]

hello friends,
Maine bahut saare indicator use kiye hai forex market to got good and strong signal about forex market.. Par mujhe MACD(Moving Average) ke alawa koi bhi indicator samajh nahi aata ki kaise kya trend ka pata chalta hai.

Even, i am not able to understand what the values means to which enter during the use of indicator and how will work.Jaise koi SMA 15 use karta hai koi SMA 20.
I don't understand how differ from each other.

I had not found answer of my question after the long search into forum decided to open the thread so that people had similar question like me can benefited by this way.

So, i want to answer of my question from fellow members, experts, professional and senior member over the forum that how actually indicator and how can we understand indication?