In what ways to extrasolar planetary systems differ from our own solar system?
Solar systems can differ in many ways.
There are many factors which influence the formation and evolution of a solar system.
The size and brightness of the star will define where the habitable zone is.
The activity of the star will determine how much radiation is received by any planets. Some stars have massive emissions on a frequent basis.
The size and type of planet will influence the shape of the solar system. Jupiter is massive enough to influence other planets orbits. It is also capable of evicting a planet from the solar system. Other solar systems are known to have planets more massive than Jupiter. They will have a bigger influence.
Rocky planets can have different compositions. A rocky planet with an iron core can have magnetic field.
Giant planets like Jupiter and Saturn can be gas giants made of mainly Hydrogen and Helium. Others such as Uranus and Neptune are ice giants consisting of methane, ammonia, water and other compounds.
The distance of a planet from its sun impacts its temperature. Planets close to their suns will become tidally locked.
Basically every solar system will be different in some way. As more exoplanets get discovered we gain more insight into the diversity.