The television broadcast standard throughout Europe (except in France and Eastern Europe, which use SECAM). This standard broadcasts 625 lines of resolution, nearly 20% more than the US standard, NTSC, of 525. There are 25 frames (50 fields) per second making up the picture. The 625 line, 50 field sequence is always linked to a 50 Hz mains frequency.

The NTSC is the organization that developed the analog television standard currently in use in the USA, Canada, and Japan. The NTSC standard combines blue, red and green signals modulated as an AM signal with an FM signal for audio. The picture is made up of 525 lines with 30 frames (60 fields) per second. The 525 line, 60 field sequence is always linked to a 60 Hz mains frequency.

The television broadcast standard in France, the Middle East, and most of Eastern Europe, SECAM provides for sequential colour transmission and storage in the receiver. The signals used to transmit the colour are not transmitted simultaneously but sequentially line for line. SECAM processes 625 lines, a maximum of 833 pixels per line and 50 Hz picture frequency. SECAM is used as a transmission standard and not a production standard (PAL is typically used).
Just to be awkward there are two types of SECAM - V (vertical) and H (horizontal). The countries that first started transmitting in SECAM (France and French-speaking Africa, Russia and the various former Soviet bloc countries) use SECAM-Vertical, the colour coding information being put in the vertical spacering. With the advent of teletext this presented a problem as the text information is also put in the vertical spacering! To allow both the SECAM colour coding system and teletext to be used together the colour coding information was put in the horizontal spacering. All the countries that were in the 'second wave' of SECAM (Greece, Saudi Arabia, Iran, Iraq etc) broadcast in SECAM-Horizontal.
SECAM video recorders are basically the same as PAL machines with the appropriate coders fitted with the exception of VHS which, unlike all other formats, can only record either Vertical or Horizontal. Other composite recording systems (1"C, U-matic, BVU etc) record both formats simultaneously. SECAM-H is also known as MESECAM (Middle East SECAM).