-:doc:`Virtual File System (VFS) <vfs>` library provides an interface for registration of file system drivers. SPIFFS, FAT and various other file system libraries are based on the VFS.
-:doc:`SPIFFS <spiffs>` is a wear-levelled file system optimized for SPI NOR flash, well suited for small partition sizes and low throughput
-:doc:`FAT <fatfs>` is a standard file system which can be used in SPI flash or on SD/MMC cards
-:doc:`Wear Levelling <wear-levelling>` library implements a flash translation layer (FTL) suitable for SPI NOR flash. It is used as a container for FAT partitions in flash.
Due to the restriction of NOR flash and ESP hardware, accessing the main flash will affect the performance of the whole system. See :doc:`/api-reference/peripherals/spi_flash/index` to learn more about the limitations.