Answer:
Liquidity of an asset refers to how easily convertible the asset is to cash or so called liquid money.
Most Liquid - A $5 bill
This is already cash so it is the most liquid there is.
Second-Most Liquid - The funds in a money market account
Funds in a money market account are the second most liquid because most often they can simply be withdrawn from the fund. There might be limits on the number of withdrawals allowed though within a period.
Third-Most Liquid - A share in a publicly traded company
A share in a publicly trade company ranks here because to realize the cash, one would need to sell the share first.
Least Liquid - Your house
Your house will be the most difficult of these to liquidate as it will involve a much longer process to eventually get it sold and realize cash. The process will include but will not be limited to, advertising, hiring realtors, inspection etc.
