Do you discuss work related ideas on Slack, Whatsapp or Emails? You don't need multiple channels for such discussions with this feature. Discussions or as we call it Collaboration@Work is a feature which allows employees, teams, departments and groups cross organizations to create formal discussion forums which could include topics like Sales, Customer Care, Compliance, Learning & Development etc. The Discussions feature is a central repository of the company's knowledge base where all employees have access to this feature.
Who can create a Discussion? It depends on the privileges in your organization. The right to create discussions can be given to any employee though typically this privilege is with HR or Top Management. However, all employees are open to participate and contribute to discussions.
Discussions is a very powerful tool when used properly!