PAL

PAL means *P*hase *A*lternating *L*ine and is a way of encoding colour information in the analog TV signal.
Strictly speaking it refers only to the method of modulating the underlying black and white signal with the additional colour information.

Today the acronym is most often used as a synonym for the 576i TV-norm which describes the resolution of 576 vertical lines and a refresh-rate of 50 interlaced half-frames per second.

In the context of digital broadcasting (DVB) or digital media (DVD, BD) the term PAL is most often used to discriminate it from the NTSC norm.
When we speak of PAL vs. NTSC this usually relates to the different refresh rates (50Hz PAL vs. 59.94Hz NTSC) mostly accompanied by the different verical resolutions (576 lines PAL vs. 480 lines NTSC) of the two systems.

See also:

• NTSC
• SECAM
• 576i
• 480i

Further reading:

• Wikipedia article on PAL
• Television Standards-Formats and Techniques