How to sync two folders in one go?

Ask Fedora
9

Please help me to understand the difference and how to memorize it:

In the treeS, there are three folders
/treeS

  • aS
  • bS
  • cS

Under current directory, there are existing files and folders, but no aS/bS/cS .

  1. what are the difference of:
    a. rsync -a /treeS/cS ./
    b. rsync -a /treeS/cS/ ./
    c. rsync -a /treeS/cS/. ./
    or even
    d. rsync -a /treeS/cS/* ./

I just want to sync /treeS/cS so that it will result in pwd/cS . Which of a/b/c I should use?