What is the difference between blocks and fragments in a group?

The output of a mke2fs command is as follows root@localhost:~# mke2fs /dev/xvdf mke2fs 1.42.9 (4-Feb-2023) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 6553600 inodes, 26214400 blocks 1310720 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=4294967296 800 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks:     32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,     4096000, 7962624, 11239424, 20480000, 23887872   Allocating group tables: done                             Writing inode tables: done                             Writing superblocks and filesystem accounting information: done What I don't understand over here is this line > 32768 blocks per group, 32768 fragments per group I understood that the sectors(generally 512B) in a hard disk are first divided into small groups. The groups of sectors is called as blocks. In every block group I have 32768 blocks. What I don't understand here are the fragments. What are they? What does it signify? And if its possible to alter fragments in my FS.