The main difference between a video cassette recorder (VCR) and a digital versatile disc (DVD) player is the kind of media each uses. A VCR relies on analog magnetic video cassette tapes, which is entirely different than the digital disc-based technology used in DVDs. The tapes in VCRs usually provide lower image quality than DVDs and often have a lot of noise in the images that may appear as static. DVDs are generally able to provide a better image and hold more data. One other major difference between a VCR and a DVD player is that most VCRs have the capacity to record, while this is a less common feature on DVD players.
VCRs are analog, while DVDs are digital, which could be considered one of the most fundamental differences between a VCR and a DVD player. On a basic level, digital technology uses numbers to store data and is designed to be read by computer equipment. Analog media uses the power and distance separating electrical pulses to translate data into something usable. In many cases, digital media technology is naturally more versatile, and this is definitely true in the case of DVDs in comparison to VHS tapes. DVDs can be used to store everything from movies to computer programs, and while there have been tape technologies with more versatility, VHS tapes are generally only used for audio and video.
Another big difference between a VCR and a DVD player is the durability of the different kinds of media. In this area, both have different advantages. VHS tapes tend to degrade over time, but they're very tough when it comes to resisting physical damage because of their sturdy outer casing. DVDs can easily be scratched, which can totally destroy them, but if they never suffer physical damage, they are potentially semi-permanent and don't experience any data degradation.
A VCR and a DVD player can both be used to record programs for viewing later, but it is not as common for DVD players to include this feature. This is partly because DVDs are in direct competition with digital video recorder technology that relies on a hard disc, a generally a more popular way of archiving programs digitally. In the case of video cassette players, there are a few that don't have the ability to record, but most of them do, and this has almost always been a big selling point for the technology.