The term DEN MACHINE can be solved by the four-letter word TIVO. TIVO is a digital video recorder (DVR) developed and marketed by Xfinity, a subsidiary of Comcast. It allows users to record television programs to a hard drive, pause and rewind live TV, and access streaming services such as Netflix and Hulu. TIVO also offers features such as series recording, which automatically records all episodes of a show, and the ability to search for shows by title, actor, or director.