There must be a collecting well in the basement. These floor drains lead to the collecting well through the embedded pipes in the bottom plate. In the future, a water pump will be installed in the collecting well to discharge the water to the outside.
Not sure if there is a drain around. When pouring the floor, there may be open ditches around it. The basement floor is sometimes very thick-generally in the range of 50-200 (mostly 100 or more), and the thickness will reach more than 200.
Happy life! Please adopt what you understand.