How to understand "Singapore real estate property rights"?

There are three types of real estate property rights in Singapore: permanent title deed, 999 title deed and 99 lease title deed.

1. There are two levels of land sold by the government to developers, namely 99 and 999. The former is generally used to build mid-range houses with various facilities, while the latter is generally used to build luxury houses such as townhouses and detached houses.

In order to save land, apartment buildings developed and built by the government where ordinary people live are generally built with more than ten or even twenty floors. Within the prescribed time limit, the land can be sold. After the expiration of the use period, the land use right together with the above-ground objects will be owned by the government free of charge, or it can be renewed when it expires, but it must be paid to the government according to the land price valuation.