Driving profile choice (Eco) in general

Hello, who can explain to me what technical differences arise when choosing Eco gg normal or Snow? The guide writes 3 sentences that you save with Eco Sprot for example…haha… don’t find any details. U.A. happens when turning on eco the instant deactivation of start/stop and display becomes darker. No idea what else and what happens with other modes. Maybe there is an official overview or someone can explain that? Also, according to the instructions, should each engine ustart resette the driving profile selection to “normal”. With me, the one in Eco stays when I last had Eco (so the guide is not correct?) Hope for information and discussion