What's the difference between .ARF and .WRF?

.WRF (WebEx Recording Format)

• Use a .WRF player to watch .WRF recordings, i.e.,
  WebEx sessions you've recorded directly onto your computer.
• Edit .WRF files using an editor you install separately.
• Convert .WRF recordings to Windows Media Video (.WMV) format using the editor.

.ARF (WebEx Advanced Recording Format)

• Use an ARF player to watch .ARF recordings you've downloaded
  from WebEx and saved to your computer.
• Record .ARF files using Network-Based Recording (NBR).
• Navigate your recording using a table of contents.
• See the session's attendee list, video, and more on separate panels.
• Convert .ARF recordings to Windows Media Video format (.WMV) or
  Flash (.SWF) using the .ARF player.
• Make basic edits on your WebEx site—no standalone .ARF editor is available.