There are 3 main analog video standards in use around the world.

PAL (Phase Alternating Line)
NTSC (National Television System Committee)
SECAM (Séquentiel Couleur à Mémoire—Sequential Color with Memory)...

Like PAL, SECAM also has 625 scan lines and is based on 50 Hz. SECAM uses two color difference signals and modulates them onto alternate lines, and through a built in delay both are available at the same time. This eliminates phasing, and with FM transmission, and color recovery so good, saturation was unnecessary.

While NTSC and PAL transmit the luminance and chrominance signals simultaneously, SECAM transmits luminance continuously and generates only one of the two chrominance signals on any given line. The frame rate is 25 frames per second (It has a field rate of fifty fields per second) to provide compatibility with the European electrical supply frequency, and the number of scanning lines is 625 as in PAL. SECAM has a horizontal rate of 15.625 KHz. SECAM suffers from the visibility of the sub-carrier signals particularly in the mid-gray and white signals. This visibility detracts from its black and white compatibility....

The following countries use the SECAM system for television broadcasting.

Africa...

There are five varieties of SECAM:

1. French SECAM (SECAM-L)
French SECAM (SECAM-L) is used only in France, Luxembourg (only RTL9 on CH 21 from Dudelange) and Tele Monte-Carlo Transmitters in the south of France....

SECAM, also written SECAM (Sequentiel couleur a  memoire, French for “Sequential Color with Memory”), is an analog color television system first used in France. A team led by Henri de France working at Compagnie Française de Télévision (later bought by Thomson) invented SECAM. SECAM uses the same resolution as PAL (625 lines) but transmits the color information sequentially: R-Y on one line and B-Y on the next.

SECAM is used sparingly around the world and can be found in France, parts of Greece, Eastern Europe, Russia, and Africa. It is, historically, the first European color television standard....