Join Date: Apr 2007
Location: Hartley Wintney, Hampshire.
Car: MGF Trophy 160, MGB.
Edd, DIN and ISO are standards organisations. The DIN term is an industry wide size for car radios, so a single DIN fits in a standard rectangular hole in the dash (no idea of the dimensions but it's bound to be in mm with several decimal places!!) 2 DIN or Double DIN is a slot twice the height of a single DIN one.
The International Standards Organisation or ISO poke their oar in everywhere. In the case of car radios they set an industry wide standard for how the connections on the back of the radio are presented. Both in plug type and style and which pin on which plug is 12v/ground/LH speaker/etc..