I decided to work on a simple write up as this is one of the questions that was asked mostly from clients and prospects.
For private properties (or condos), the monthly maintenance fees are generically this is referred to as the "service charged", and this amount would be split up equally with the share value (such as your floor area).
The maintenance fund is meant to cover the regular maintenance, like the upkeep of the private properties' facilities. From interior to exterior management to even its utilities and security, the maintenance fund covers most of the things required to keep the private property going. Also included are your parking space, and insurance (if any)
A sinking fund is usually what that is set aside for costlier upkeep. It could be to make any changes to a structure or replace certain parts or facilities.
Each year, the owners and committee (appointed) would decide how to distribute the service charge collected into maintenance and sinking funds.
That being said, it is common to look at or even take into account the monthly maintenance fees as they are part of the cost of owning a property as an investment as well.
There are other factors that you could take into account, such as the age of the property, or the area, which will affect the amount of the generic service charge as well. Do make sure to check the monthly service fees whenever you're looking at a private project.