When it comes to talking about servo amplifiers you must first understand what the servo is before you get into the amplifiers of the servo. A servo is basically a machine or a mechanism that senses error feedback from a machine, and then corrects the problem, or the performance of the mechanism. There are many different products and machines out there that use servos to help correct minor problems within the machine before it actually has to be repaired by person.
For instance the cruise control in cars have servos on them that help monitor the speed you have set your vehicle to travel on, and if the speed starts to get to fast or to slow, the servo will send a signal to correct the minor problem, and the speed of the vehicle will be reset to the specific speed you set your cruise control to.
A servomechanism is basically the same exact thing as a servo its just a more technical name for the device. Although the name of this device does have some difference, the servomechanisms are basically what the title says they are servos that are placed inside different mechanisms to help monitor them to make sure if a problem arises, or something minor goes wrong the servomechanism will then try to correct the problem before it gets to big.
Although sometimes the servomechanism will not be able to fix or correct the problem and thus the problem will be to big for the device to handle and someone will have to repair the problem by hand. This doesn’t happen very often but sometimes the servo will fail, and then both the problem and the device will have to be fixed and replaced.
When you are talking about a servo there is one thing you have to combine with the servo for the device to work, and that is the servomotor. The servomotor is basically what the title says it is, its a motor that is used to power the servo so that the servo can re-adjust the problems that arise it the device, or mechanisms its over-seeing. Most servos use an electric motor, but some also use different motors like hydraulics, and different magnetic motors, as well to help power the servo.