Video: NTSC vs PAL

Technically SECAM cameras internally store data in PAL format, so for all practical purposes, when dealing with VHS signals over RGB signalling, PAL/SECAM is 25 fps, 576 lines per frame, NTSC is 30 fps, 480 lines per frame. Both are interlaced, PAL is higher resolutioin, lower frame per second rate.

The following deals somewhat with over the air transmissions.

NTSCPALSECAM
National Television System(s) CommitteePhase-Alternating LineSéquentiel couleur à mémoire
VarietiesNTSC I, NTSC II
NTSC III came about due to digital television routing during the 1980s; all aspects of NTSC III are rigidly mathematically defined.
PAL B, D, G, K, I, PAL-M, PAL-N and PAL-NC. Fear.French SECAM (SECAM-L), used in France and its former colonies
SECAM-B/G, used in the Middle East, former East Germany and Greece
SECAM D/K, used in the Commonwealth of Independent States and Eastern Europe (this is simply SECAM used with the D and K monochrome TV transmission standards
Lines per frame525 lines per frame, of which 480 visible lines.625 lines per frame, of which 576 visible lines.625 lines per frame, of which 576 visible lines.
Refresh rate59.94 interlaced fields (60 Hz/1.001), (29.97 full fps). 50 Hz – 50 interlaced fields (25 full fps). Note: Motion pictures are usually shot at 24 fps, resulting in 4.2% speedup when telecined.50 Hz – 50 interlaced fields (25 full fps).
Color encodingluminance-chrominance encoding system. Quadrature amplitude modulated subcarrier carrying the chrominance information is added to luminance video signal.  Red and blue are transfered together.phase-alternating line encoding system.  Quadrature amplitude modulated subcarrier carrying the chrominance information is added to luminance video signal.  Red and blue are transmitted together resulting in bleeding in high contrast scenes.fixed frequency subcarrier modulated by color signal.  Frequency modulation is used to concode chrominance on the subcarrier, Red and Blue luminance are transmitted one at a time, separated by delay line.  As color information is approx. the same between two consequitive lines, information from preceeding line is used to make up for bandwidth shortage.
BenefitsGreat vertical color resolution, esp in NTSC VHS or NTSC laserdisks.higher then NTSC line resolutionhigher then NTSC line resolution, good color separation thanks to luminance bein transferred separately.
Shortcomingslow number of lines per frame. color bleedingcolor bleedingVertical color resolution is 1/2 of that  NTSC or PAL.