Traditional intranets focused on top-down communications. These early intranets were pretty well limited to pushing content and messages from the company's management team to the rank and file. While a good start, this one-way communication flow was a key contributor to the under-utilization and outright failure of many intranets.
Hence the growth of 'social intranets' that drive employee-to-employee communication and knowledge sharing.
The DNNPro.com Forum app drives much of this 'virtual water cooler' capability through department or project team specific groups. And unlike a physical water cooler discussion, all DNNPro forum discussions are fully searchable and evergreen.