Not really. That's like saying that all lamps over 300 watts are to be called lamps and those less than 300 watts are to be called light bulbs. A difference between control voltage and switching voltage isn't really a discriminator either.
Is the "condenser" in the ignition of your pre-1980s car not a capacitor, just because the auto mechanic calls it by that name?
There is a difference. Contactors are usually used when driving motors. They have a higher voltage rating to prevent arc-over when stopping a motor. Relays are often used in control circuits and have lower voltage ratings. N.B. There is a voltage rating for the coil that pulls-in the contacts, and a different voltage / current rating for the contacts that drive the load..
Festo's BionicKangaroo combines pneumatic and electrical drive technology, plus very precise controls and condition monitoring. Like a real kangaroo, the BionicKangaroo robot harvests the kinetic energy of each takeoff and immediately uses it to power the next jump.
Design News and Digi-Key presents: Creating & Testing Your First RTOS Application Using MQX, a crash course that will look at defining a project, selecting a target processor, blocking code, defining tasks, completing code, and debugging.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.