NAND Flash, nor flash, SPI flash, on-chip RAM, off-chip RAM

 Flash has the characteristics of power-down data storage. If Ram power-down occurs, data is lost, but Ram speed is higher. Theoretically, there is no limit on the number of writes, But Flash does not.

Compared with other types of flash, NAND Flash has the advantage of high erasability and high write speed. However, Bad blocks may occur during use and use.
Can be used only after processing. It is mainly used for data storage, and most USB flash drives are NAND Flash.

Nor flash read/write timing is similar to SRAM, but it only writes a small number of times and is slow. Because its read timing is similar to SRAM, the read address is a linear structure and is mostly used for program code.
Storage.

SPI flash is similar to NAND flash, but the interface is converted into a serial IO port, and the write speed is slower. It is mainly used for data storage that does not need to be changed frequently.

There is no essential difference between in-chip SRAM and out-of-chip. The main difference lies in speed and performance.

Can be used to store data, except for Spi flash, other programs can be stored and run. The CPU User Manual needs to be verified for the specific supported type.