Microwave ovens have always been useful appliances, but most people use them for reheating leftovers or cooking up frozen meals. They're rarely used for more robust cooking tasks, but inverter microwaves are starting to change that.
Steady Power
In traditional microwave ovens, cooking power is controlled by cycling energy to an internal device called a magnetron. Magnetrons can only deliver a full burst of energy, so when you set your microwave to low, the magnetron is turned off part of the time and on part of the time. Inverter microwaves allow for fine-tuned control of the heat for a constant steady cooking temperature, and this helps them work more effectively.
Fine Temperature Control
Because of the way they work, inverter microwaves allow for many different temperature settings. This means that they can be used in ways that other microwaves cannot. For example, inverter microwaves can be set to a very low temperature for use in keeping food warm. People have even used them to effectively slow-cook meats.
Modern and Efficient
Most inverter microwaves are being sold as top-of-the-line items, and the companies are adding a lot of extra bells and whistles to them, like child locks for example. They also use significantly less power than traditional microwaves, so they might be a good purchase for environmentally conscious consumers.