Nowadays it is impossible to built serious site without choosing software for its support and update.

Notion Content management includes  wide spectrum of software nowadays, from the set of short scripts allowing to add news or press-releases on one page of site, to valuable publishing systems supporting the processes of workflow (chain author-proofreader-editor), providing different charts of access differentiation, automatically creating the "linked" documents, etc.
The choice of the best CMS (Content Management System) for your project (or corporative site), first of all depends on your budget, expected complex of he site and technical providing. Instead of just comparing possibilities of different CMS, you should decide what you really need. Before choosing software or company which will create it read and think about  few questions which will help you to define the parameters of the future system and your Requirements. But you should remember that there is no universal CMS and software without defects.