: This could refer to "Double Data Rate" (relating to memory/RAM drivers or firmware) or "Dance Dance Revolution" (relating to game assets or song packs), depending on where you downloaded it. To help me identify the exact contents for you: What is the total number of parts in the set? Where did you download the file from? What is the total file size of the combined parts?
The file is the second volume of a multi-part compressed archive. Because the archive is split, you cannot view its full content by looking at part 2 alone; the computer needs the entire set to reconstruct the data. How to Access the Content sc23063-DDR.part2.rar
: Select "Extract Here" or "Extract to [Folder Name]". The software will automatically pull data from part2.rar and any subsequent parts to recreate the original file(s). What this file likely is Based on common naming conventions: : This could refer to "Double Data Rate"