When I first heard about it 4-5 years ago it seemed just like a buzzword that was thrown out to get more funding for your startup or just to sound more "posh". I also heard it being described as "glorified linked list" on few subreddits.
But considering how the "craze" around it has not died out and a few of online search seem to land you on pages of crypto bros I would like to ask:
What exactly is blockchain?
Where is it used?
Is it an actual viable tech or just a forced one (aka a bubble)?