NTSC & PAL are just two of them
Here's a link to the various TV standards.
NTSC is used in the US and some other countries. Over the years, the NTSC standard has evolved to the current NTSC-M and NTSC 4.43 levels.
PAL is used in most of Europe. There are variations like PAL-B, PAL-D, and PAL-H.
There's also SECAM used in some countries, primarily French speaking ones.
If you want to see what standards are used in a given country, here's a reference.
Oh, yes. Don't forget the new HDTV standard(s).
It isn't quite as bad as the computer industry where an old joke goes, "Standards? Sure. We have standards. Thousands of them."