Direct current is generated by the following items.

1. Rectifier

A rectifier converts alternating current (AC) to direct current (DC).
Since electronic devices such as personal computers and smartphones operate with direct current, rectifiers generate DC from AC.
Typical example: AC power supply used for charges

2. Battery

Batteries, such as dry batteries and those used in automobiles, generate direct current through chemical reactions inside the cells.

3. Solar panel

Direct current can be generated when light hits the semiconductors used in solar panels.
Since households use alternating current, this direct current is converted into alternating current for use.