The EFI partition (also called ESP) is a storage partition for all UEFI bootloaders, applications, and drivers needed for a UEFI boot. It is an OS-independent partition that's automatically created by Windows whenever you install a new Windows OS on a disk. It's formatted in FAT32 file format and almost always exists as a 100MB partition. The EFI partition is protected by Windows, and you can't delete it using Disk Management.