In this picture what you see it the loft feature, it consists of different work planes with different sketches on those planes, then you mold them together, basically you just extrude shapes to different shapes.
Circular pattern
This is what we call the circular pattern feature, we put one hole in the disc, and them multyplyed it all around the disc.
revolve
This would be a Hand Grip on a bike handle, all we did was take a sketch in the shape of it and revolve around the hole in the middle, it is actually hollow inside.
mirror
All this object is is the product of the mirror feature, i selected all the features on the left side and mirrored them onto the right side.