This is a vector imaging format used in the CorelDRAW editor. It has a template that can be applied for other designs, including styles, grid parameters, page layout and other parameters. The CDT template allows for the creation of several images in one style without changing the settings in manual mode.
DOT is a template file created by Microsoft Word, a word processing application. The DOT file provides a solution for situations where many similar documents with the same font and layout are required with simple changes between them needed, like names and places for example