\b matches word boundaries.

pattern between // is a regular expression pattern that matches on to the string object.
in this case the pattern is 0*$ which is:
0 - is the character 0
* - is whats called quntifer, it stating how many times should the character on the
left side of it should be counted. * - zero or more times.
$ - stating that that you want to match to th end of the current string.

Since the two arguments are both booleans we can use them directly when comparing. This solution asks if I'm employed and (&&) not (!) on vacation. Since this is Ruby, the last executed line in a method is automatically returned.