Linux cp replication error prompt

  linux, question

My root authority, execute
cp wendang wendang1
Hint: cp: omitting directory ‘wendang’
I checked on the internet and said that wendang had something to do with the recursive -r parameter. I did try it, but! The weirdest thing is
ls -la wendang
total 8
drw-rw-r— 2 root root 4096 feb 25 04:26 .
drwx——— 6 user1 user1 4096 feb 25 05:07 ..
There are only …. there are no documents. what exactly is the omitting error mentioned above?

Without -r, the directory will be ignored regardless of whether there are files in the directory.