The difference between joking and joking.

The difference between joking and joking is that nouns are singular and plural, and phrases have little difference in meaning, all of which mean "joking"

Making jokes is making jokes, and making jokes is making more than one joke.

Play a joke on sth;

Play a joke on sb.

Make fun of sth. Tell a joke about something.

Make fun of sb. Play a joke on sb.