: The file is compressed using the RAR (Roshal Archive) format to reduce its size.
: This likely refers to a content provider or platform. FC2 is known for various types of digital content, including videos. FC2-PPV-4512638-1.part1.rar
# List parts present in the current directory ls -1 FC2-PPV-4512638-*.part*.rar | wc -l : The file is compressed using the RAR