Q. To understand the concept of tension and the relationship between tension and force.

This problem introduces the concept of tension. The instance is a rope, oriented vertically, that is being pulled from both ends. Let and (with u for up and d for down) represent the magnitude of the forces acting on the top and bottom of the rope, respectively. Assume that the rope is massless, so that its weight is negligible compared with the tension. (This is not a ridiculous approximation--modern rope materials for example Kevlar can carry tensions thousands of times greater than the weight of tens of meters of such rope.)
Consider the three sections of rope labeled a, b, and c.

At point 1, a downward force of magnitude acts on section a.
At point 1, an upward force of magnitude acts on section b.
At point 1, the tension in the rope is.
At point 2, a downward force of magnitude acts on section b.
At point 2, an upward force of magnitude acts on section c.
At point 2, the tension in the rope is.