What is a report and where do we use them !!

What is a report ?

A textual work that relays certain information or recounting events in a representive form!! - visual + aural.

Can there be reports for anything ?
Yes !! - Elvaluation
           - Observation
           - Official Docs
          - News Report
          - Incident Report
          - Music
          - Weather
          - Health and Saftey
          - Radio Report
          - Personal Report
          - Medical

Is it always formal ?
- Why ?
Depending on the target audience . Also Aural reports are different to be formal !!