A covered porch is what you might see on a farmhouse. The covering provides protection from the sun's rays. The porch is large enough to set furniture on, so people can sit in the shade and enjoy a nice, cold drink on a hot day.
A sunroom is a screened-in porch. It allows you to enjoy a nice breeze on a beautiful day, but the thin screening around the perimeter of the porch keeps insects and other pests out.
The breezeway works as a covered walkway between the house and the garage, as well as a relaxing place to set outdoor furniture.
A courtyard in front of the house actually counts as a porch. The courtyard is a broad space that can be filled with just about anything---a garden, fountain, statues---you name it.
Old Victorian houses usually come to mind when a wraparound porch is mentioned. The porch runs along the front and continues on to one or both sides of the house.