What's the difference between "translation inerter" block and "mass" block in simscape?

here are their help page

translation inerter

mass

For example, what's the difference between the two system?

Answer 1

[Sabin]

The Mass block represents an ideal mechanical translational mass.

The Translational Inerter block represents a device that has force proportional to the rate of change of the relative velocity across the ports. It is essentially a two-port inertia that works on the velocity difference between the ports, not the absolute velocity. An inerter is the mechanical equivalent of a capacitor. An inerter with one port connected to ground essentially behaves as a mass with the mass equal to the inerter’s inertance.