Need Help In Understand Layout_weight="1"

In the camera app layout it has: camera.xml:

Solution 2:

Layout Weight is the relative weight of various layout elements. If one element has weight 1, and others have weight 0, the first element will take all the space available, except the bare minimum needed by the others. If one element has weight 1 and another weight 2, the first takes 1/3 of the space, the other 2/3.

Best regards.