There are three main ways we can characterise most peoples online internet and mobile activity and presence. Let me state up front that these distinctions are purposely blunt, but do act as effective and critical distinctions, especially when talking to people about how and why they can manage their online identities.
Josie Fraser characterises these as: personal, professional and organisational. The article is a very useful intro to some of the problems around personal identity management.
rWorld2 