The Forex is a fight between the bulls (buyers) and the bears (sellers).
When the bulls are in control (uptrend), they work hard to score the next point at resistance. The first point of resistance is called Resistance 1, the second, Resistance 2, etc.
When the bears are in control, they work hard to score the next point at support. The first point of support is called Support 1, the second, Support 2, etc.
When you know the support and resistance levels, it gives you a good idea where to exit the trade. After the bulls or bears score a point, they usually pull back and build their strength for the next battle.
Applying the Pivot Indicator is another way of viewing support and resistance lines.