Thanks for this explanation! It is really short and easy.
I have read some sentences about the topic since writing my comment above and @pradeep.sidd68 [wrote](https://steemit.com/steem/@berniesanders/why-aren-t-more-of-the-top-witnesses-running-supporting-full-nodes#@pradeep.sidd68/pradeep-sidd68-re-berniesanders-why-aren-t-more-of-the-top-witnesses-running-supporting-full-nodes-20180802t204203088z) 5 hours ago that ***"Nodes that fully verify all of the rules of block chain are called full nodes...
Full nodes ensure the perfection and accountability of block chain transactions.. which not widely understood."***  

Thanks to both of your explanations, now I have a very basic, brief knowledge about what a node and a full node is.