Generator is an electromechanical device that generates electricity by transforming mechanical energy into electric energy. It generates electricity based on the electricity and magnetism work rules. It is driven by the wind turbine and hydraulic turbine of the system. The electricity generated by the system is for power station application and industrial application as main AC power.
Inverter is a power electric device that can convert one current into another current. This device is mainly used to transform DC into AC. The inverter takes AC directly from AC source and converts it into the DC by rectifier. The converted DC is used to charge the battery. At the same time, as AC is used in the industrial and household system, the DC from the battery will be converted into AC by the inverter. This system can be used to supply power for household electricity system in case of power failure. The inverter does not need external power to support its work. Although both the inverter and generator can improve the work efficiency, their functions are totally different.
How does a generator work?
Portable generator needs fuel to support its work. The difference of AC and DC is that electron can move in two directions in AC but can only move along one direction in DC. As AC can bear higher voltage, it will loss less energy when moving along a long distance. 
This is why AC is used to supply power for most houses and buildings. In this way, most household appliances shall adopt AC. Otherwise, they need to transform the AC supplied to houses and buildings.
Traditional generator cannot transform the current from one form to another form. Generator works by transforming mechanical energy into electric energy. Under most situations, generator is used to supply power for household system. The large-size generator can be driven by coal, natural gas or nuclear power. But portable generator is usually driven by gasoline and diesel. In case of power failure, these fuels are used to generate power for the construction site or the buildings. The generator can be designed to generate DC or AC. Most power station and some low power consumption system adopt AC. What the traditional generator can do is to generate electricity. If the power voltage needs to be changed, the transformer shall be adopted. The inverter generator is similar with traditional generator. The inverting generator also generates AC but can invert it into DC, which produces a smoother and stabler power flow. It can save more oil and can operate more quietly than traditional generator.
How does an inverter work?
An inverter can transform DC into AC and deliver the current to different direction by the switch control. The filter can be used to smooth the waveform and fix the frequency. Multiple filtering methods can be used by different inverters based on the required output smoothness. The rectifier can be used to transform AC into DC. A big difference between generator and inverter is that inverter can only work with power supply and it cannot generate power by itself. Unless it is a part of the combined machine tool, otherwise the inverter can only transform DC into AC.
One of the main functions of the inverter is to supply power for different electronic products in cars. Vehicle generator usually generates DC, which is not compatible with most devices that adopt standard household outlets. Now, most cars have an accessory port that can be connected with the car power inverter, allowing to supply power for small-size TVs, cell phones or other electronic devices. Some small-size car inverters are designed to plug into the cigarette lighter of the cars.
