what does it mean /period/ when i open a chart indicator

im a noob can someone explain to me when i open a chart indicator like RSI or parabolic SAR in the window i have an option thta says period and a number,what does that mean

Generally it is how many bars or candles the calculation is based on. The bars on the open chart that the indicator is attached to.

so if in the period window i place 15 that means it calculated by only the last 15 candels,stochastic oscillator has [%K period] in one spot and [%D period] in the other what does that mean,i dont wana bore anybody can u direct me to some web page where i can lear this

Altought I don't use indicators I find a refreshing that someone actually tries understand how the indicator works. Most newcomers just randomly plot some indicators without knowing how they work.

http://en.wikipedia.org/wiki/Stochastic_oscillator

Here is a good introduction to the Stochastics Osc.

im reading the babypips school its great but theres some things that are missing sometimes a deeper explanation

If you are using MT4 and want to know more about the indicators that come with MT4 you could look at MetaQuotes.

Here is another site with descriptions of technical indicators.