RS232 communication interface
The Electronic Industries Association (EIA) has set up an asynchronous transmission standard interface on personal computers. Fruit industry association (ElectronicIndustriesAssociation EIA) set of asynchronous transmission standard interface. In general, the RS-232 interface is 9 pins (DB-9) or 25 pins (DB-25), and in general, there are two sets of RS-232 interfaces on personal computers, called COM1 and COM2.
HDMI high-definition multimedia interface
HDMI is a digital video\/audio interface technology, a special digital interface for image transmission, which can transmit audio and image signals at the same time, with a maximum data transmission speed of 48Gbps(version 2.1).
rs232 is a serial port used to transmit small amounts of data such as swiping. HDMI is a high-definition data interface used to transmit large amounts of data.