Why Defragment , is it important to be scheduled or is it danger to make it a lot at the hard drive life?

The process of defragment is so important to the performance of the hard disks because it arrange data stored on the hard disks so the write and read speed improve and it is not danger for the hard disk life instead it is good for it 

Basm Allah Alrahman Alrahim

I think defragment more than once a month is danger ! why ?

look to this link or see the next figure

what is happen in that figure first you will see files at any partition before defragment (i.e fragmented ) , the files may be separated at many parts at the hard disk or sectors , then when you make defragment the files parts or sectors will be putting behind each other in a way look like cut and past ( and it will use the end of hard disk like store for replacing sectors) , the problem may appear here ! ?

if you are making that daily and at the same time you are a fan of downloading file especially big files and move them to other partition or you are fan of installing and uninstall new programs that mean your hard will make changes to the sectors places within a very short time and that destroy the hard very fast (look like you are setup windows ever few days ) , and don't forget that the Operating system either make changes and replaces to files all the time at your hard disk

observe that the end part of the hard disk or the partition that will be used as a storge to replace will be used all the timeALL the above will make bad sectors very fast

Note

1 - you don't need defragment in Linux OS

2 - you don't need defragment in SSD hards

It make hard faster than any moment Because transfer empty size to be alone and use size alone on drive