In general:
Law: rules that apply to all.Acts: situation specific rules that apply to specific people and specific circumstances (Students Act, Housing Act, etc.)Regulations: Rules that are Legally binding, generally describing Implementation details of the Act/Law.Rules guidelines/instructions on how to do something correctly. They are not legally binding (ie, 'club rules').Note that Rules can also be described guidelines that are not legally binding, but can get you expelled (school rules/club rules).
Bills are proposals to be turned into Acts or Laws.