Excellent. We already mentioned that a point represents a single location on Earth. It has a shape and length of 0. This has both its advantages and disadvantages. On one hand, points take up very little space in spatial databases. Calculations performed with points are also quick. On the other hand, we can't precisely define the shapes of objects represented with points. They are therefore suitable representations of simple objects whose shape does not matter to us, such as tram stops, ATMs, post boxes or road signs.
At this point in the course, it is worth getting to know two functions that can be used to work with points:
ST_Y(geometry). These functions return the X and Y coordinates, respectively, of a point.
The above query will return the X coordinates (longitudes) of all ATMs in San Francisco.