On my machine, fdisk -lu /dev/sda displays following output:   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *        2048    73947135    36972544   83  Linux/dev/sda2        73949182    78139391     2095105    5  Extended/dev/sda5        73949184    78139391     2095104   82  Linux swap / SolarisWhat is this blocks unit? Is one fdisk block a 1KiB? Where does this unit come from?
blocks column in output of fdisk
fdisk
You should know some concepts like sector, track, cylinder to understand block. Here is a simple definition:Blocks and clustersThe Unix communities employ the term block to refer to a sector or group ofsectors. For example, the Linux fdisk utility normally displays partitiontable information using 1024-byte blocks, but also uses the word sector tohelp describe a disk's size in the phrase, 63 sectors per track.You can read more in this link.