This is the format that is used in the OpenGL and Microsoft DirectX development environment. It is used to store bitmap images of user interface environments and textures. It allows you to store information in compressed and uncompressed forms. It is used for texturing game models and storing entire textural arrays to create games and 3D-software applications. DDS is used to develop the latest-generation video game consoles. It makes it possible to compress texture blocks 'on the fly', which increases performance when you run the application.
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