Files with DWG extension represent proprietary binary files used for containing 2D and 3D design data. Like DXF, which are ASCII files, DWG represent the binary file format for CAD (Computer Aided Design) drawings. It contains vector image and metadata for representation of contents of CAD files.
Introduced and documented by Microsoft, the Rich Text Format (RTF) represents a method of encoding formatted text and graphics for use within applications. The format facilitates cross-platform document exchange with other Microsoft Products, thus serving the purpose of interoperability. This capability makes it a standard of data transfer between word processing software and, hence, contents can be transferred from one operating system to another without losing document formatting.
You can also convert DWG into many other file formats. Please see the complete list below.