One little ingredient makes all the difference.
You're going to drink it, just for the taste of it.
This was one of the slogans used to promote Diet Coke when it was first introduced in 1982.
The taste of it differs from both 'full fat' coke and Coke Zero.
Coke Zero and Diet Coke are both the sugar free alternatives to Coca Cola, with the latter having been around since 1982. Coke Zero on the other hand is already 11 years old - yes, over a decade, feel old yet?
How the world has changed:
Diet Coke 1982
Coke Zero 2006
In a charming reminder that 2006 was basically the 1950s, the British advert for Coke Zero compared relationship intimacy to Joseph Stalin's planned economy.
Why do they taste different?
The two sugar free drinks do differ in taste - Coke Zero is meant to taste the same, whereas Diet Coke has its own flavour.
The difference is citric acid, which is only in Diet Coke.
Coke Zero, uses sodium citrate instead, in order to make it taste like full fat coke.
Fans of Coke Zero, due to be scrapped from production, can look out for 'Coke No Sugar', which the makers promise will taste just like regular coke too.