You've probably seen those on-foot chase scenes in movies like Casino Royale, where the escapee vaults over obstacles and lands from scary heights with cat-like grace. That's parkour and freerunning in action — and they're similar. The difference between the two, however, is in the mindset.
Image by alexander.s.farley.
Developed from military obstacle course training, parkour is running, swinging, jumping, and climbing from point A to point B in the quickest way possible. Freerunning is similar, but it emphasises the flashy side of parkour, with fancy flips and stylistic acrobatics. It's more like an art of movement to express your creativity with your environment, the KKParkour blog explains.
In essence, parkour is more "practical" (like for those obstacle course-style races). It's also a viable way to incorporate fitness into your life since you get to develop coordination, balance, and total-body strength, all the while having fun and learning useful movements. If you're not comfortable with the thought of navigating around urban objects, many major cities have parkour gyms that offer a safer environment for you to learn.
Just don't expect to be good right-off-the-bat. In fact, this scene from The Office, where the show's characters perform embarrassingly dangerous stunts while yelling "parkour!", is a (hilarious) masterclass in what not to do when you're learning parkour.
How to Do Parkour Safely [KKParkour]