The monthly costs are what you have to pay every month.
In a coop it's one amount, called maintenance. It's real estate taxes combined with the upkeep of the building, water and heat usually (may include doorman, management, etc).
In a condo you have two amounts, Common charges which is that same upkeep of the building and separate your real estate taxes. The amount you see there is what it cost per month, but you pay these quarterly (RE Taxes)