ROM is Read-Only Memory: A solid-state semiconductor memory that can only read data stored in advance. Its characteristic is that it cannot be changed or deleted once it is stored. It is usually used in electronic or computer systems that do not require constant data changes, and the data does not disappear because the power is turned off.

The data stored in the ROM is generally written in advance before being loaded into the entire machine. The entire machine can only be read during the work process, unlike the random memory, which can be quickly and easily rewritten.

The data stored in the ROM is stable, and the stored data will not change after the power is cut off. The structure is relatively simple and the reading is convenient, and thus it is often used to store various fixed programs and data.