Conciliation and mediation are ways for a third party to help with negotiations and to identify the terms of a possible settlement.
Conciliation is required by the Labour Relations Act before a strike / lockout position becomes legal. A conciliator is a government-appointed third party that assists the two sides in clarifying their positions to each other. Mediation is not legally required, but is available if the two sides voluntarily agree.
A mediator (often the same person as the conciliator) takes a more active role in negotiations, suggesting possible ways to settle the issues in dispute. However, neither a conciliator nor a mediator has the power to impose a settlement. Both conciliation and mediation are phases in the overall negotiations process.