Dvrs have a program guide to help you find and record shows, but there are also some important differences. these include whether or not the model has a built-in hard drive for storing shows, the number of programs you can record at one time, and how easy it is to set up and use the dvr. unlike some of the other models, which require you to supply an external hard drive to record shows, our products has a built-in 1tb hard drive capable of recording up to 150 hours of hd-quality video. it also supports 4k videos with hdr. and there's a slot for adding an external hard drive if you need even more storage at androomeda, we have all the required products necessary for you to save your data.