Hi @jinny1985,
No problem.
May I suggest these posts as quick reads with good information on this topic. These are an important source of passive income and their numbers are on the rise. I think expertise in this area is increasingly in demand.

https://steemit.com/kr-exchange/@shortsegments/a-review-of-recent-good-masternode-explanation-articles-and-two-very-unique-masternode-coins

https://steemit.com/kr-exchange/@shortsegments/masternodes-explained-in-easy-to-understand-language