A charger is a device that charges only batteries, usually with a charge indicator, such as a battery car charger. He can't call the adapter.

Switching power supply:
Switching power supply is a method of converting 220V voltage into low voltage DC, which is different from the traditional power frequency transformer. The power supply using this switching voltage technology is called switching power supply, chargers and power adapters are currently using switching power technology. At present, switching power supply is widely used in almost all electronic equipment because of its small size, light weight and high efficiency. It is an indispensable power supply mode for the rapid development of electronic information industry.
In addition, the development and application of switching power supply are of great significance in energy saving, resource saving and environmental protection. The power electronic devices used in switching power supply are diode and IGBT (insulated gate bipolar transistor). GTR is difficult to drive and has low switching frequency. It is gradually replaced by IGBT and MOSFET.

The power adapter:
Power adapter is a small portable electronic equipment and electronic appliances power supply conversion equipment, generally composed of shell, power transformer and rectifier circuit, according to its output type can be divided into AC output type and DC output type, according to the connection mode can be divided into wall plug type and desktop type. Widely used in language repeater, Walkman, notebook computer and other equipment. The power adapter can be used not only for power supply, but also for an electrical charge, just like the power adapter in a notebook. It can charge a computer and power it. For example, the power adapter of LCD, and the power adapter of printer.
Most laptop power adapters can automatically detect 100 to 240V alternating current (50/60Hz). Basically all notebooks have an external power supply connected to the mainframe with a single wire, which reduces the size and weight of the mainframe. Only a few models have the power built into the mainframe. There is a nameplate on the power adapter that indicates power, input and output voltage and current.

A charger, a switching power supply, and a switching power adapter can (but not necessarily) be a thing.
The concept of switching power supply is to pay attention to the internal characteristics of the items, the concept of charger is to pay attention to its use, and the power adapter is to highlight the auxiliary of the main equipment.

The popular analogy is as follows:
Porcelain bowl -- switching power supply -- the bowl is made of porcelain.
The purpose of a bowl (note that a charger is not made from a switching power supply, and a bowl also has a glass bowl)
Tableware - - power adapter - - - refers to the dining service (power adapter also has transformer AC output, ordinary linear rectifier voltage output, as well as the battery box. Tableware, spoons, etc.