SMPS Full Form is Switched Mode Power Supply. D.C. to A.C. convertors and D.C. to D.C. converters can be categorized as SMPS. In simple terms, it is the power supply, which uses switching regulator to stabilize and control output voltage. This is done by switching off and switching on the load current.
The benefit of such power supplies is, they reduce overall power loss and contribute to greater power conversion. The term SMPS generally refers to items, which can be directly connected to the mains. It can also be used to produce source power or be connected to an external supply. In effect, it can be a complete power supply.