A campfire must be fueled with wood in order to function.
Campfires stop working if exposed to rainy weather without a roof.
Campfires stop working if exposed to strong wind without 70% cover.
Active campfires create smoke. If the campfire is created within an enclosed space, the smoke can build up causing any players inside to be Smoked and take 2 hp/tick damage. To safely place a campfire indoors, the interior space must be large enough to let the smoke naturally dissipate or be vented out through a chimney or other holes.
The smoke appears to have a 1 block diameter, so to use multiple campfires, larger or more chimneys will become necessary.
The Fire Effect for the Campfire extends for about 8 meters (Measuring from the closest you can stand without setting yourself on fire).
Wet players dry significantly faster when close to Campfires.
It can be used for cooking (in combination with a Cooking station or a Cauldron or a combination of both).
It is required for a bed to be used for sleeping, but will not prevent it from being a spawn point.
Destroying the campfire with a hammer will yield back just the 5 stones used for construction. All wood that was used as fuel and for the initial construction will not be dropped.
With 1/10 fuel, a Campfire will last for 1 hour and 23 minutes. At maximum capacity a Campfire should burn for 13 hours and 53 minutes. This duration is the same for the Bonfire.
A campfire will take 10 damage every time it sets an entity on fire.
One of the few base structures that isn't a priority target for creatures.