into the directory cd #
Example: cd /usr/local/tomcat8.5 # enter the directory /usr/local/tomcat8.5
Example: cd .. # from the current directory, quickly returned to the parent directory
Example: cd ../ .. # from the current directory, rapid return on two directories, and so on
Example: cd ~ # returned under their own home directory. If the user is root, then back to the / root directory under, if an ordinary user, then back to the / home / directory under their own.