Why bootable SSD and or USB device with no HDD?

I see many posts here from PC/Laptop user's who have no bootable HDD
Repeat- No hard drive in their systems.
My question is: What is this all about?



The problems that they post would not exist if they had a hard drive. Money is not the problem because they are using expensive SSD devices. A laptop only has one screw holding the hard drive in and a hard drive is a most simple install on a desktop and help is available here .

Something about gaming?

Anonymous2014-07-10T18:05:51Z

HDDs have long been the slowest path in a data stream. A second, probably more apt answer is the noise reduction achieved by removing the HD and slowing fans to a crawl.

Anonymous2014-07-10T18:42:06Z

Login your BIOS and pick Option Boot

?2016-03-02T14:58:12Z

Stop worrying about your computer and focus on people in need.

?2015-04-06T22:57:23Z

https://m.youtube.com/watch?v=zdunF62fvuI#https://m.youtube.com/watch?v=QxKbNQGX--s#https://m.youtube.com/watch?v=3ror9iEGZew#