Different between sudo and sudo su?

Sudo runs a single command with root privileges and Sudo su switches you to the root user account after that all your commands will be executed with root privileges.

How to check size of a file or directory in Linux?

We could check the size of a file or directory using the below Linux command.

du -sh <folder/directory name>

How to move or rename a directory in linux?

If you are moving or renaming a directory within the same directory then use the below command

mv <directory-name> <new-directoy-name>

e.g. mv new-folder new-2016

PS: If you want to move to a different directory then pass the complete path instead of just passing the folder/directory name