ADR covers a range of resolution processes, primarily:

Facilitation

Negotiation

Conciliation

Mediation

Arbitration

Facilitation:

The role of the facilitator is to help parties come to a decision.

Usually, facilitation occurs where there is no real conflict or disagreement between the parties.

Resolutions reached are not legally binding.

Negotiation:

Probably the most common form of ADR.

Very flexible as the parties are free to negotiate between themselves- no reliance on a third party to adjudicate.

Parties work with their legal advisors to resolve disputes and reach an agreement.

A non-binding process, but parties still need to be aware of what they want to achieve.

Parties usually have the worst case and best-case scenario they are prepared to accept in mind before negotiating, and this creates a sort of area in which successful negotiation can occur.

The society offers a chance to try your hand at negotiation, in the annual commercial negotiation competition, open to all students regardless of degree or experience.

Conciliation:

Parties look to reach a settlement with the help of a third-party conciliator. 

The conciliator is asked to provide a non-binding proposal to the parties, which is where it differs from mediation.

Parties are free to choose the conciliator, meaning they can look for a specialist on the matter. 

Parties rarely meet face to face, the conciliator acts as a go between for parties to interact with each other through.

Mediation:

An independent third party adjudicates between the other parties to find a mutually acceptable outcome. 

The goal is to find a resolution or settlement.

Mediators tend to deal with more volatile situations (compared to facilitators), where conflict or disagreements may have arisen between parties.

The solution is not binding, the mediator can only try to help structure an agreement, as with facilitation.

For it to become legally binding, a legal agreement containing the resolution must be signed.

Arbitration:

More formal than the previous procedures, which makes it useful when dealing with technical matters, or private matters for which security is important.

Very useful for international disputes, to avoid dealing with multiple courts and jurisdictions. 

Arbitration is legally binding and is handled by an arbitrator who is once again a nominated third party.