What shape am I?

I have 6 square faces.
I have 8 corners [vertices].
I have 12 edges.
What 3d shape am I?

I have 3 faces.
One face is curved.
Two faces are circles.
I can roll on my curved face.
What am I?

I have a point.
I have a curved face.
I have a circle face.
I roll around in a circle shape.
What am I?

I am a rounded ball shape.
I have one curved face.
What am I?