What is a masternode?

My updated video on what masternodes are. People often ask me what a masternode is when I mentioned it so I figured that this video would help. For my post on if I think you should invest in a masternode see my blog: http://exavierandcryptos.site/index.php/2018/08/26/what-is-this-site-and-should-i-invest-in-masternodes/