Type command -- tell you about other command

whatis type
type (1p) - write a description of command type
type [builtins] (1) - bash built-in commands, see bash(1)
[root@vikas 18-feb]# type ls
ls is aliased to `ls --color=tty'
[root@vikas 18-feb]# type dir
dir is /usr/bin/dir
[root@vikas 18-feb]# type banner
banner is /usr/bin/banner
[root@vikas 18-feb]# type rm
rm is aliased to `rm -i'
[root@vikas 18-feb]# type rmdir
rmdir is /bin/rmdir
[root@vikas 18-feb]# type [
[ is a shell builtin

type -a ls

It works some what like which, but bash builtin.