T.V

In different parts of the world Television is broadcast in different standards the reason for this is money, if it all played on the same then the companies would not be able to make as much money as people could tune there T.V's to receive the different channels elsewhere in the world. this means that instead of the program being brought by Sky so that it can be played in the UK and Fox so it can be played in America, Fox could buy it and we could watch it through them, there are also different copyright laws in different parts of the world which means that they might end up not being payed for the program at all. there are four main types of format, they are:

NTSC- national Television Standards Committee   

This has recently been replaced due to the digital swich over to, ATSC - Advanced Television Systems

NTSC runs at 30P which gives you a smoother motion that PAL
SECAM- System for Electronic Color with Memory. {Sequential Coleur Avec Memoir}
SECAM is an early attempt of  color Television and it's transitions are more robust over longer distances

PAL- Phase Altering Line

PAL runs at 25P which is less smooth but it automatically cancels out hue errors with phase reversal