Intranet System network connectivity within organization and nowhere outside the organization. User can access only particular webpages or any other related information from it and this will have a different IP address. Here you have to be an authorized user to access webpages as well
Internet System network connectivity for everyone, anybody can access any online webpages from any places across globe. Anybody can view any webpages unless other webpages are restricted for selected online user through User ID and Password.