Final answer:
Tension is a pulling force along a medium, such as a rope or cable, always acting parallel to its length. It is important in physics as it relates only to forces that pull, not push.
Step-by-step explanation:
Tension refers to the pulling force that acts along a medium, particularly evident in a stretched flexible connector such as a rope, string, cable, or wire. This force is parallel to the length of the medium and can only exert pulls, not pushes—illustrated by the saying, "You can't push a rope." When an object is supported by a rope, the force on the object due to the rope is named a tension force.
Consider a scenario where a person is holding a mass suspended on a rope. The tension force pulls outward at the two ends of the rope. This is a key concept in physics, particularly when studying forces and mechanical systems. The origin of the word tension is from the Latin term meaning "to stretch," much like tendons in the human body that carry muscle forces to other body parts.