Joining two files by using the shell command cat

I’ve currently download two files, which are simple splitted from one file.
Now i want to join these files. This can be done with a simple shell action like:

cat file.wmv.002 >> file.wmv.001

 
But attention, it’s better to make a backup before trying to join the files.
The direction of the files is, the second file is ‘>>’ attached to the first.