A Digital Video Recorder (DVR) is a device that allows you to record, store and play back television programming. It works like a VCR but instead of recording to a VHS tape, it records to a hard drive or other digital storage medium. Some DVRs can also be connected to the internet and allow you to access and stream recorded content from anywhere, as well as record TV shows or movies from online streaming services. This makes a DVR a great tool for recording your favorite shows or movies and watching them at your convenience, or for time-shifting your viewing so you can watch live TV at a later time.
Source - https://en.wikipedia.org/wiki/Digital_video_recorder