For questions related to the RAMPS controller board - The RepRap Arduino Mega Pololu Shield, or RAMPS for short, is an expansion shield for the Arduino Mega designed to fit the entire electronics for a RepRap 3D printer in a small, low cost package.
RAMPS 1.x is a family of popular 3D Printer controllers, which is a shield that sits on top of an Arduino Mega. The most commonly used is the 1.4 version.
Additional information and a full list of features can be found at the RAMPS RepRap Wiki page.
See these definitions from the RepRapWiki:
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