The following information was provided by Chanel last year on a leaflet for its customers. It helps to make the differences between the products more understandable for me.
Parfum - The quintessence of No. 5. The freshness of Neroli, the sublime harmony of May Rose and Grasse Jasmine. Absolute luxury.
Eau de Toilette - A subtle interpretation. A Sandalwood note is beautifully emphasized amid the base notes of precious woods.
Eau de Parfum - Bright top notes, and a more obvious touch of Vanilla with a smooth and silky radiance.
Elixir Sensuel - Sensuous fluid gel glides on luxuriously and leaves the body delicately scented with the Parfum's pure heart of May Rose and Grasse Jasmine. Captivatingly soft.
Eau Premiere - Ylang-Ylang from the Comoro Islands is more discreet, giving softness and freshness to the top notes. Grasse Jasmine is given greater transparency. A silky-smooth harmony and the delicate facet of No. 5.