Natural gas is naturally occurring and is found in coal beds and landfills of decaying anaerobic organic matter among other places. It is almost odorless but a chemical substance is added to give it a smell for safety reasons and enable easy detection in case a leakage occurs. Natural gas is not easily compressed which makes it difficult to store in tanks and transport. It is therefore pumped and delivered to homes through gas pipelines so homes with a natural gas line are best suited for this kind of fire pit. Natural gas being lighter than air does not sink to the ground when released to the air, it therefore poses less danger than propane gas.
Natural gas fire pits have similar functionality conveniences like the propane gas fire pit. However since gas is fed to the fire pits through a gas line that is connected to homes, natural gas fire pit have a permanent fixture. The fire pit cannot be not moved from place to place. The best feature and perhaps the property that makes these kinds of gas fire pits stand out from the other fire pit fuel types is that being  the risk of running out of gas in the middle of entertainment is nil. Fuel never runs out unless of course something unfortunate happens to your connection to gas line.
Depending on the location on where you want your fire pit located, the initial cost of installing the gas line and fire pit could be expensive due to a number of reasons but once that is out of the way natural gas fire pits are the least expensive in the long run and are easily maintained.
This kind of fire pit would do well as a backyard fire pit providing an outdoor cool ambiance on nights when friends and family gather