A carbon credit is what is bought and sold when dealing with voluntary carbon offsets. For every tonne of CO2 that a project manages to absorb or otherwise reduce, a carbon credit is issued. Carbon credits are certified by international standards and held in registries like the Gold Standard registry (international credits) or the Emissions Trading Register (New Zealand).

Voluntary carbon offsetting is to compensate for unavoidable carbon emissions. To do this, organisations support projects that positively impact the environment and reduce or avoid carbon emissions that would have otherwise contributed to climate change. If the positive impact of this support negates the negative impact they have, ie: if the emissions avoided equal the original emissions of an activity, that activity is said to be "offset".

Voluntary carbon offsetting is to compensate for unavoidable carbon emissions. To do this, organisations support projects that positively impact the environment and reduce or avoid carbon emissions that would have otherwise contributed to climate change. If the positive impact of this support negates the negative impact they have, ie: if the emissions avoided equal the original emissions of an activity, that activity is said to be "offset".