Tether
In short
A tether is a flexible cord, rope, or fixture used to anchor a movable object to a fixed point. It can also connect two moving objects together, such as a vehicle and a trailer.
In plain words
It is a strong string or chain that keeps something from drifting away. It holds an object in a specific place or keeps it attached to something else.
A simple example
A dog on a lead is attached to a tether to stop it from running into the road. A balloon tied to a weight uses a tether to stay in one spot.
Why it matters
Tethers are vital for safety in activities like rock climbing or space walks. They also allow for controlled movement in towing and animal management.
Easy to mix up
Do not confuse a tether with a permanent anchor, as a tether is usually flexible and allows for some movement.