China DOS Union

I created two plain text files, abc and def, and the contents of the files were the same as their filenames. I selected the two files, chose to add them to an archive with WinRAR, selected "store" as the compression method, named the archive abcdef, then clicked OK. After it finished, I renamed abcdef.rar to abcdef.txt, but when I opened it, the contents were not abcdef at all, but a pile of garbled text. Of course abcdef was there, but it was separated in the middle by garbled text. Can everyone tell me what is going on? But when I used the Dos command copy with the /b parameter to merge the two files above, the result was correct.

Does nobody know? Can a moderator help me?

WinRAR is not merging files at all. It is only putting the files into one package, just without compressing them.

But then how do you merge files? Some people said it can be done. I was originally going to forget it, since having the copy command is enough, but then I thought of the fact that I have many small avi files, and their names are in Chinese. Do I really have to rename them all one by one into English, and then type the filenames one by one when using the copy command? That's not very realistic, right? So that's why I did it this way. Sorry to trouble everyone again.