This will be less and less necessary as computers and hard drives get faster.

Camera Media

Most digital cameras shoot a format that might not be easy to edit or color grade depending on the editing system.  They may be in raw, un-color-corrected format intended for colorists.  Or they may be in highly compressed codecs, like H.264, which allow them to record on the slower digital media. 


It simply means to copy the file into an editable file, and in most cases might take a few hours time for each shoot day.  Nothing to be afraid of.  Analogous to film transfer.  The original is kept for possible color grading or re-sizing.  In most cases the files are transcoded into ProRes Quicktimes or MXF files.

Raw Files

If the file needs to be debayered, this is a longer process and is helped by cards like the Red Rocket or simply fast computers.  A Gamma like REDLogFilm may be chosen to make a transcoded Log file which can me the new master for color grading.

Log Files

This file will look flat, so some will chose to transcode to files that look normal.  This is fast, and editing software will soon just display it properly without any transcoding, but retain the log info in the file for color grading.

Compressed Files

H.264 files (Canon 5D, Panasonic AF-100) as well as other hard to edit files will be transcoded into bigger files to keep color from degrading as much if color grading is done to the files, at least in offline.  Transcoding will ease the editing process greatly.