Different transmission methods: RS-232 adopts a single end transmission method, and its data signal is relative to the signal ground, usually used for point-to-point communication; RS-485 adopts differential transmission mode, allowing multiple transceivers to be connected on the bus, and is commonly used for multi-point communication.

Different transmission distances: RS-232 is suitable for short distance communication, generally not exceeding 15 meters; RS-485 is suitable for long-distance communication, with a transmission distance of up to 1.2Km.

Different communication capabilities: RS-232 is usually used for one-on-one communication;

RS-485 can support one to many communication methods, namely multi-point communication. Different level standards: RS-232 has a higher signal level, which can easily damage the interface circuit chip and is not compatible with TTL levels; The interface signal level of RS-485 is lower than RS-232, which is compatible with TTL level and convenient for connecting with TTL circuit. Different application scenarios: RS-232 is mainly used for short distance, point-to-point communication scenarios, such as the connection between computers and external devices;

RS-485 is suitable for long-distance communication and high anti-interference requirements, such as industrial automation, transportation equipment, power systems, etc.