1. ► ksh, zsh and bash all extend sh.

2. ► You cannot use a shell not listed in /etc/shells.

3. ► An user cannot change his/her finger information.

4. ► ls --color is not a POSIX compliant option.

5. ► set and export do identical functions.

6. ► /etc/password stores user password in plain text.

7. ► libtermcap makes use of /etc/termcap.

8. ► Login shells can only be started by the system at login time.

9. ► csh is an extended version of tcsh.

10. ► PATH variable is common across shells.