For sake of convenience, we will be referring to both the portable propane and permanent natural gas types as simply ' Gas Grills ' unless there is something specific about one particular type being discussed. Gas grills are easily started, reach cooking temperatures quickly, maintain constant temperatures, and are easy to shut down when grilling is completed. It is great for those quick grilled meals after work. Even the 'non-barbecuer' in the family will find the Gas Grill easily manageable.
Propane is under a higher pressure and thus uses smaller orifices on the burner jets.
Natural gas is much lower pressure and a larger orifice is necessary to obtain the needed gas flow to heat the grill. Some grills have adjustable orifices and many do not. Most gas grill manufacturers, however, offer replacement orifices to convert from propane to natural gas. Simply contact them. Make sure that you get a clear, blue flame with not any or very little yellow.