OTP (One time programmable) is a special type of non-volatile memory that can only be programmed once, and once programmed, the data is permanently valid.
Compared with MTP (multi-time programmable) such as EEPROM, OTP has a smaller area and does not require additional manufacturing steps, so it is widely used in low-cost chips. OTP is often used to store reliable and repeatable data, such as: Boot program, encryption key, emulator configuration parameters, etc.
A type of memory that means one-time programmable: after a program is burned into the IC, it cannot be changed and cleared again.