PVR stands for "personal video recorder," while DVR stands for "digital video recorder," and both devices are essentially the same. A PVR is similar to a VCR although it records data from the TV via a digital format, while a VCR records it in an analog format. DVRs are devices that are connected with the video signal and the TV.
Over time, the DVR began to replace the PVR due to the introduction of HD and digital TV. This introduction urged manufacturers to show that their products worked with newer digital sets and that they were compatible with the new digital format. Prior to this change in technology, the PVR was associated with the ability for users to select shows and programs from personal preference. A notable difference between the two is that a PVR permanently stores files onto a hard drive, while a DVR temporarily stores files on a smaller hard drive.