Hi Sheryl. On Windows 10, you have a number of choices to be able to play DVDs. One of those choices is to use PowerDVD, there are other choices too from alternative providers both free and commercial. The core feature of PowerDVD that no one else really does properly at the moment, is PowerDVD has full menu bluray disc support.
You needn't be concerned with NTSC or PAL. Every DVD player software will handle this automatically. Its just different standards to do with technical aspects of the DVD.
You do need to be concerned about region coding if you want to watch DVD's from multiple region codings. Some DVD players enforce DVD and Bluray region coding, some do not. For the DVD and Bluray players that do enforce region coding, there is a way to workaround it by using other software to do the decryption and to fake any DVD or Bluray region code a user might want, its called AnyDVD from Slysoft. The problem that Cyberlink faces in licensing all the technologies for Bluray and DVD is that all the licence agreements would no doubt force Cyberlink into doing certain things, like respect Bluray region coding and respecting prohibited user operations like queing in certain Bluray ads/notices etcetc.
If people want full menu bluray support and region free, most people will use PowerDVD and AnyDVD together.