What is Digital Signature?

welcome here i'm viral parmar back with a Digital Signature as Promise, so while i heard about digital signature I've imagined something it's a something tech which is include some handwritten signature into soft form, but but but i was totally wrong it's far different from it, confused?? let me explain for you we all have a diffrent identity in the term of Signature we all are used signature to access our data in bank, exam, Cheque and attendence also, so all we know that computer science world is the mirror of our copy so one of the computer say that "hey human you have a signature then why i haven't" and developer run their mind and invent Digital signature at 1976 for Computer's.