The Digital Versatile Disc (usually just shortened to DVD) is an optical disc format first released in Japan in late 1996 and the US in early 1997. Although it took until 2002 for DVD rentals to overtake VHS rentals and 2003 for DVD sales to finally overtake sales of the VHS, the DVD got popular in a relatively short amount of time and ruled throughout much of the 2000s.
Alongside the older Compact Disc (CD), the DVD is one of the most successful optical disc formats. The familiar DVD has been so successful that it managed to lead to the rapid demise of the VHS in 2006 and still continues to overtake Blu-Ray sales to this day. It ended up being far more successful than many of its prototypes like the 1970s LaserDisc and the VCD released just a few short years before the DVD in 1993. The DVD was truly revolutionary in becoming a standard in optical video disc releaes, still being produced to this very day in 2024 (in spite of streaming services gaining popularity over the last decade or so).
Odds are, you probably own at least 1 DVD player or device with a built in DVD drive and at least a small collection of discs. Sony's Playstation 2, released in 2000, really seems to have been responsible for the surge in popularity of the DVD during the aughts as it functioned as both a game console and a DVD player as well. It also ended up being the best selling game console of all time.
In addition to their usage as a video storage format, DVDs can also be used for computer data storage, in DVD camcorders with the miniDVD standard, photo storage (as with CDs, but with a higher storage capacity than the CD), and more. Blank DVD and CD discs can also still be found quite easily in many drug stores and online in various formats (blank DVD formats include DVD-R, DVD+R, DVD-RW, DVD+RW, and DVD-RAM). Blank Blu-Ray discs are also available for purchase, though they aren't as easy to find as blank DVDs and CDs.
A standard, single sided, single layer DVD5 disc can hold 4.7 GB of data, which is about 2 hours of video in standard definition (480i). However, there are DVDs that are dual layer, dual sided, or both that can hold more hours of video (unless you're willing to sacrifice video quality in exchange for holding more video content on a single normal disc), though these are harder to find than your standard single sided, single layer DVD disc.
That beig said, there were a few failed disposable types of DVD including the infamous DIVX in the late 90s and the related FlexPlay of the mid - late 2000s.
I have a pretty decent collection of DVDs myself, both from my childhood and some that I've gotten quite recently. I even own the complete seasons 1 - 6 of Spongebob on DVD. :)