what is blockchain? i dunno and wanna try to study from scratch n find my journey begins

i am on my study jjourney

what should i further my study about?

hci
data science
networking
crypto
cyber-security
blockchain

yes some one suggest to me block chain. thank you Prof ...
but what is it, he said go and study
study from journals
but for today i find video to study and would like to put here for my future reference
on what i study on my first day of block chain....

again

happy learning new knowledge to me...... study n earn peace in your journey... yeayy