Buying carbon credits gives you the ability to offset your emissions. “Burning”/”Retiring” them means you’re actually using them to offset your emissions and claiming it for its environmental benefit. Kind of like planting the seeds you bought. Then that carbon offset is permanently taken out of circulation and can no longer be traded or sold to anyone else. Whenever a credit is used and emissions are offset, it’s important that the carbon credits are actually burned so that they can’t be used again and you can claim its environmental benefit.