If you are using Linux or Unix-like OS and need to create a new directory, you're most likely going to use the mkdir command:
$ mkdir newdir
or you can specify a full path to it (in this example I'm creating a subdirectory in my /home/greys homedir)
$ mkdir /home/greys/newdir2
If you specified a wrong name or incorrect location, you can use the rmdir command to remove the directory like this:
$ rmdir /home/greys/newdir2