Presenting slides in front of a big audience is just one application of PowerPoint, and probably not the one that is most commonly used. Here are a few others:

• Corporate knowledge database
• Product catalogue
• Project management and planning tool
• Word processor
• Story boarding tool
• Group brainstorming tool
• Animation editor
• System design tool
• To do list and meeting minutes recording tool

A 1980s presentation design tool ended up being the operating system that power most communication inside a company.