Why is the foreground the most important in photographic composition?

Foreground is the best way to enhance the sense of space in the picture. A good prospect can enhance the sense of space in the picture and make the photo look like a three-dimensional picture instead of a simple picture. On the other hand, the foreground is also the most difficult part of composition. Choosing a good prospect needs the echo of all parts of the picture, not simply looking for a tree or a house. Therefore, it is very important to learn to look for prospects.