I didn't post on the other thread, since it was off topic.. . And to be honest, I don't have much to add after reading the above posts. Sparring is a vital part of training in any combat sport or martial art, whether we're talking about fencing, boxing, tkd, karate, or whatever.
Sparring means the same thing no matter what the activity; to engage in a free form exhibition of your art/sport against a partner or opponent. However, what differs from school to school/art to art/sport to sport are the rulesets, i.e. degree of contact, degree of speed, types of movements allowed, etc.. .
In my school, the "normal" sparring session is all stand up striking with hands and feet. It has many benefits as a training tool, which include but are not limited to the following:
- testing proficiency of distancing, timing, footwork, speed, control, precision, and technique in "real time" against a live partner.
- experience of taking a hit (REALLY IMPORTANT ONE), and learning that you can take a hit and keep on going.
- testing proficiency and efficiency of offensive and defensive techniques and combinations of techniques.
- competition with others and oneself.
- it's generally considered the most fun part of class that everyone looks forward to in my dojang.
I do throw some expanded rulesets from time to time, including multiple opponents, takedowns, grappling, open hand techniques, weapons, and what not, but that's not the mainstay.
I know different arts/sports have different goals associated with sparring. For instance, I have a friend that practices pukulon silat, where all sparring is done in 1/2 speed, with very light contact. My friend explains that, in this art, every movement is meant to be a fatal one, so it's kinda difficult to spar full speed with any of their techniques. So obviously, there are limitations depending on the activity/style/whatever.