what is a solid state external hard drive
Solid-state drive A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies as memory to store data persistently. It is also sometimes called solid-state disk;[1] the word "disk" is inappropriate since SSDs do not have physical disks. SSDs primarily use traditional hard disk drive (HDD) interfaces, such as SATA and SAS, greatly simplfying usage of SSDs in computers.[2] Following the initial acceptance of SSDs with HDD interfaces, new I/O interfaces like M.2 and U.2 have been designed to address specific requirements of the Flash memory technology used in SSDs.
File system Linux supports numerous file systems, but common choices for the system disk on a block device include the ext* family (ext2, ext3 and ext4), XFS, JFS, ReiserFS and btrfs. For raw flash without a flash translation layer (FTL) or Memory Technology Device (MTD), there are UBIFS, JFFS2 and YAFFS, among others. SquashFS is a common compressed read-only file system.