What's the difference among NTSC, PAL and SECAM?

There are currently 3 standards in the world of composite, color- encoded video.

NTSC: The NTSC (National Telvision System Committee) is a standard format adopted by the FCC for television broadcasts in the United States, Japan, Canada, and Mexico. *525 lines of resolution per frame at 30 frames per second. *60Hz field frequency *requires a 6MHz analog channel for transmission

PAL: Based on a 50Hz power system, PAL (PPhase Alteration Line) is the standard format for television broadcasts in Germany, *625 lines of resolution per frame at 25 frames per second. *50Hz field frequency *Requires a 8MHz analog channel for transmission

SECAM: SECAM (Sequential Couleur a Memoire or Sequential Color with Memory) is the video format used in France, Eastern Europe, F.S.U and some Middle Eastern countries. *625 lines of resolution per frame at 25 frames per second *Color signals are transmitted sequentially (R-Y followed by B-Y and etc.)