First of all why of a sudden I have written this post? Simply because I wanted to , and I also see blogging more as a stress relieving method than anything else. So let's get right into this .
Masternodes in plain English work the same way as servers and databases work . Since you allow your computer resources to be used for the purposes of the coin's blockchain you get rewarded. The amount of coins required for a masternode differs from one coin or token to another one . Although I really doubt that tokens can use this feature as they lack their own unique blockchain - they mainly use Ethereum blockchain.
Simply in comparison PoW mining requires hardware and constant maintenance with electricity and technical support when it is needed . It means that instead of having actual coins bought to use PoS (Proof of Stake) you need to buy ASIC miners that can become obsolete after some time and might not give any profit at all. Unlike such coins that use PoW(Proof of Work ) mining mechanism PoS enabled coins are "staked" meaning that you get interest of your current holdings rather than buying some questionable hardware .
Masternodes basically work the same way as usual staking but with a minimum amount of coins needed to run it . This is to provide stability and also increase the coins value by decreasing supply and also that could be one of the reasons why they also give better ROI(Return of Investment)