Does Gerber required for PCB quote or production? What format of Gerber are most commonly used in PCB industry?

Gerber file RS-274X
Either you’re a product developer, designer, engineer, or buyer in PCB industry, you might have heard of Gerber file. Most commonly used Gerber file format by PCB manufacturers is RS-274X. Once the Gerber file is provided to PCB manufacturer, the PCB factory uses Genensis 2000, CAM350 or any other type of CAM software to read the Gerber file. Then the data could be either converted into production data, stencil data, OP or formal quoted form (IR). The accurate project information enable the PCB manufacturers to evaluate the project thoroughly.

6 essential specifications for PCB evaluation
So the Gerber file is the most essential element when clients try to get a project evaluated by PCB manufacturers. Besides the Gerber file, there’re six important specifications needed during assess stage. Board Layer count, material type, copper thickness, solder mask color, surface finish type, and board thickness. If the project is Rigid-Flex, HDI or even more complicated design, stack up drawing might be needed too.
The more completed documents you provided to your PCB manufacturer, the more precise quote you will get by them.