A slope is simply an inclined surface.I magine a ladder inclined to a wall, the more the ladder drops the more gentler the gradient (slope) become and the more the ladder moves upwards the more the steeper the gradient becomes. On a slope, the more spread out the regolith is the gentler and wider the slope. Slopes may be regolith (soil) covered or composed of bare rock. The latter usually being formed by uplift e.g faulting or in areas with low regolith production to cover the rock.A slope is composed of segments or parts called units
This is the upper unit of the slope. The gradient is usually gentler thus mass movements such as soil creep occurs. However, if the convex surface is more steeper rapid mass movements such as rockfalls may occur.
Cliff/Free Face/Fall Face
The free face is a steep scarp/cliff, usually composed of hard rock and not accumulated by debris. All material readily falls on the fall face hence the name.
This is the transportation part of all material from the convex unit. There is no gain of material or sudden change in gradient. Even if material is added the gradient remains constant as the slope grows.
This is where debris from all segments get deposited and comes to rest.
On a convex-concave the constant unit and free face are absent and at each level the gradient changes and material is readily transferred to the concave segment.