Nobody answered this right so far, so I guess it's up to me.
NTSC's frame rate: ~29.97fps (30000/1001)
PAL's frame rate: 25fps
NTSC's resolution: 525 lines (480 of which are visible) the rest are for the electron beam to get into position and captions, etc.
PAL's resolution: 625 lines (576 of which are visible) the rest are for the electron beam to get into position and captions, etc.
NTSC was the first video broadcast standard invented, and it was done in the USA in the 1940s. PAL came afterwards in 1967 in Germany.
These formats are interlaced, meaning they come in two fields per frame, all odd lines and then all even lines. (Hence 59.94 and 50 fields per second)
The reason for the change from 30 to 29.97 (30 * 1000/1001) for NTSC is the introduction of color TV, which came in 1953.
FILM runs at 24fps, and in order to get it into PAL, you must speed up the video from 24 to 25fps, NTSC doesn't get a speed up, the 24fps go through a process called telecine.. which adds intermediate frames sort of like AA BB BC CC CD DD... (similar) it's unnoticable on interlaced televisions and theres no speed up... the process can be reversed by doing an inverse telecine.
Most televisions today don't have the limitations that these formats were designed around, which is why they can play almost any format, whether it be NTSC, PAL, SECAM, etc. The only thing limiting most televisions are the VCRs and game consoles you use, which is why modded systems can play imported games without worries of signal type.
The reason for the difference in frame rates are power frequency. The USA used and still uses 60hz frequency power, most European countries use 50hz. The countries that use NTSC most notibly are the Americas and Japan (other countries mainly because they received tech from the Americas), most countries in Europe use PAL or variations, also most countries that were once colonies from Europe use PAL as well, like countries in Africa and South America.