What is the difference between a cross trainer and a elliptical trainer?

Is the cross trainer or the elliptical trainer more effective?

Do I need to maintain the ergometer? Do the moving parts inside wear out?

What is the difference between an ergometer and a recumbent ergometer?

What is the difference between an exercise bike and ergometer?

What can I train with a rowing machine?

3587 Dual Inner/Outer Thigh

3602 Cardio Strider 3.1 - Handle Adjustment

4129 Ellyptech CT3

How much flywheel mass should an ergometer have?

3582 Dual Biceps Triceps

3602 Cardio Strider 3.1

3603 Cross Rower 2.5

Which of the two devices is easier on the joints?

Can the ergometers be moved? Are the devices heavy?