Physics determines how your object physically interacts with the rest of the project. In the Physics tab, you can either turn physics on or off. Two objects without physics cannot interact with each other. At least one of them has to have physics to recognize the other as an object, otherwise they’re just pictures on a screen. Toggling Physics on gives some more options to customize your object.
Determines how much weight an object has. If an object with a lower mass runs into an object with a greater mass, the object with the greater mass won’t move much. Basically, it determines how hard it is to move the object and how hard the object hits while it’s moving.
Determines the “speed limit” for the object. This is usually used to counter gravity, but it applies to all directions of movement. The higher the drag, the lower the speed limit.
Angular drag is similar to drag, except it applies only to rotational forces.
Lock Rotation - Toggling it On restricts the object from rotating while the scene plays.
Lock X Position - Toggling it On restricts the object from moving left or right while the scene plays.
Lock Y Position - Toggling it On restricts the object from moving up or down while the scene plays.
Toggling it on gives the object a constant downward acceleration similar to real Earth gravity.