We usually connect the printer to Windows using USB and Wifi, but for some models, the system also needs to install the printer driver. Calling the printer on Android is slightly different.
Before Android 4.4, a third-party solution was needed to implement the printing function, or a protocol for communicating with the printer was implemented. After 4.4, Android introduced the Print class as a printing tool class, such as PrintHelper for printing. Bitmap, PrintPdfDocument to print the document.