How are accounts created on websites [closed]

How are accounts created on websites [closed]

References

Reference NO 1

http://www.pcmag.com/article2/0,2817,2342599,00.asp

Reference NO 2

http://www.smashingmagazine.com/2010/06/11/how-to-permanently-delete-your-account-on-popular-websites/

Reference NO 3

http://www.ieee.org/web/accounts/

Reference NO 4

https://www.waveapps.com/

Reference NO 5

https://accounts.google.com/SignUp?dsh=-4903794664528357143&service=lh2

Reference NO 6

http://www.boutell.com/accountify/

Reference NO 7

http://webapps.stackexchange.com/questions/28009/find-a-list-of-all-my-accounts-for-all-websites

Reference NO 8

https://appleid.apple.com/