Biker, I don't know if this will be much help, but here's a purely technical explanation from the help files on the SW I use:
In their analysis of charts using moving averages, technical analysts observed that in most cases the very best place to buy a share was where the gap between the price line and its moving average was at its greatest and vice versa. This led to the development of the Overbought/Oversold indicator.
The Ob/Os indicator is an oscillator derived from the moving average. It expresses the gap between the MA (moving average) and the price line as a percentage of the moving average, according to the following formula:
Ob/Os = (Price - MA) / MA x 100
Where MA is the Moving Average
You will perceive that where the price is greater than the MA (which occurs when the price is going up), the result of the above formula will be a positive number; conversely, where the price is smaller than the MA, the result will be negative. The more positive the number, the more overbought the stock is; and the more negative, the more oversold.