A single that differentiates between Aroon up and Aroon down is called Aroon Oscillator. It is found by subtracting Aroon Down from Aroon Up. It usually measures the strength of a trend. It is an indicator system which is used to find if the price is on trend nd strength of trend as well. Aroom Oscillator was developed by Chande in 1995.
“Aroon” means “Dawn’s Early Light” in Sanskrit and Chande chose that name for this indicator since it is designed to reveal the beginning of a new trend.
As the centerline, the oscillation of Aroon Oscilltier ranges from -100 ad +100. It identifies an uptrend going towards its upper trend and when moving towards the lower limit, it shows a downward trend. The closer Aroon Oscillator will show the stronger trend.
All three are comprised of a single parameter which is the number of time periods to use in the calculation.
As both Aroon(up) and Aroon(down) oscillate between 0 and +100, the Aroon Oscillator ranges from -100 to +100 with zero serving as the crossover line.
for a given time period, the calculation of Aroon(up)  is carried out by finding how much time (on a percentage basis) elapsed between the start of the time period and the point at which the highest closing price during that time period occurred.
When the price is setting new highs for the time period, Aroon(up) will be 100.
If the price has moved lower every day during the time period, Aroon(up) will be zero.
Aroon(down) is calculated in just the opposite manner, looking for new lows instead of new highs.

Consolidation

When Aroon(up) and Aroon(down) move towards the lower in close proximity then a consolidation phase continue and no strong trend is evident.

Upward Momentum

When Aroon(up) dips below 50, it indicates that the current trend has lost its upward momentum.

Downward Momentum

When Aroon(down) dips below 50, the current downtrend has lost its momentum.

Trend Direction

Values above 70 indicate a strong trend in the same direction as the Aroon (up or down) is underway.
Values below 30 indicate that a strong trend in the opposite direction is underway.

New Trend

The Aroon Oscillator signals an upward trend is underway when it is above zero and a downward trend is underway when it falls below zero.

Trend Strength

When the oscillator is away from the zero line then trend will be stronger.