To determine if industrial action is taking place, you need to identify the work that is normally performed by the relevant employees and the manner in which it is customarily performed.
Protected industrial action makes the employees taking the action (and any union organising the action) immune to legal remedies that otherwise would be available.
Employer response action is industrial action that an employer who will be covered by the agreement organises or engages in as a response to industrial action taken by employees or unions.