Velocity is always relative. This means that velocity is measured *relative to a frame of reference*.
Here's what that means:
* Imagine you're on a train moving at 60 mph. You're sitting still *relative to the train*, but you're moving at 60 mph *relative to the ground*.
* There is no absolute, universal frame of reference to measure velocity against.
What we often talk about instead of absolute velocity:
* Frame of reference: We define a frame of reference, like the ground, and measure velocities relative to that frame.
* Velocity relative to something: We often specify what an object's velocity is *relative to*, like the velocity of a car relative to a stationary observer.
The idea of absolute velocity is problematic for a few reasons:
* No universal reference point: There's no way to determine a truly "absolute" frame of reference against which all motion is measured.
* Einstein's relativity: Einstein's theory of relativity shows that time and space are relative, further challenging the concept of absolute motion.
In conclusion:
There is no "absolute velocity" in physics. Velocity is always measured relative to a chosen frame of reference.
