can anyone explain what is rsi mean?
i really not understand to use this indicator.
thanks
There are 2 types of indicators, trending and oscillating, I find oscillators best, but only use them to match end of trends by matching divergence with a H&S pattern.
it goes up and down. down sometimes up others.
Really???
Forget the language used. “Relative strength indicator” because that implies its something that indicates strength.
The RSI is basically a measurement of the change either up or down in price using an exponential moving average. This is then divided into 100. So your RSI is a measurement of two exponential averages with a setting you have selected. The reading depends on the position of the current price in terms of up or down relative to the beginning on the period being measured.
Give investopedia a search it may help you understand it.
People use it to indicate over sold and over bought conditions. They can spot divergences (mentioned in the babypips school) to try to call highs and lows. Personally I have had no edge from using it.
Here is a search to get you started:
What is RSI? on Trading Search Engine
I especially like the one titled, “Repetitive Strain Injury”. Hopefully your RSI use will be far less injurious. 
Guys , you all have giving excellent ideas , really appreciate it. 