Whenever you select something in Object Mode, a yellow dot indicates what is known as the Object Origin:
Examples of Object Origins.
By default, the Object Origin is the key point when Blender is manipulating and interacting with your selection:
- Scaling: When you scale an object, it scales outward from that Object Origin. If your origin is in the center, the object will grow equally on both sides. If your origin is in a corner, however, that side will stay stationary and the object will grow on the other side:
Scaling works outward from Object Origin
- Rotating: The Object Origin serves as the default pivot ...
