Wood fire pits do not require a steady stream of fuel to operate unlike a fire pit powered by propane or natural gas. This gives you a degree of flexibility on where and when you can burn, since you do not need a gas tank or hook up near your fire pit. Wood fired firepits are your old fashion smokey campfire style. The coals will stay hot and you can roast marshmallows.
Gas Fire Pits produce a steady flame, without the ash and wood smoke that wood fired fire pits can produce. Most gas fire pits are powered by propane or natural gas. Some gas fire pits can be adapted to be powered by one or the other. The gas powered fire pits are quick and clean to start so they work great for parties and social events.
A select few table top fire pits use venturi gel fuel. There also have a smokeless wood fire pit.
Several different companies make very high quality fire pits. For example, Blue Rhino is a large company that you will recognize from the Propane tank brand name at grocery stores. They make both propane fire pits and wood burning fire pits. You can get a great deal on their products because they are priced right!
If you want a high quality backyard firepit, your best bet is the fire pits and fire tables from Outdoor Great Room. These are the real deal! Good materials, attractive designs, and USA small business!