Sparring is practiced in many Taekwondo and martial arts schools, although some do not choose to do so. It introduces a number of advantages, although some may not be comfortable with it in classes.
For those that may not be comfortable with the idea of sparring, it should be noted that there are different levels of sparring. Full-contact sparring is sparring without hesitation at full speed, although you would build up to such contact and pace, and would be wearing appropriate gear.
Other types of sparring do not involve full contact. Many Taekwondo and martial arts spar with limited contact, which also involves limited pace as well.
Even those schools that do not use sparring in a traditional sense will practice techniques with others. These schools will normally have classmates imitate the movements, while not making contact (or little contact) to get a feel for the technique.
Take into account how a school does sparring if this is an area of concern. Full-contact sparring may not be preferable for those who do not want to have contact, say after a long day of work.
Sparring is a great way to get the truest feel for the techniques in a martial art, however. The protective gear allows schools to work on such techniques without worrying about injury.
When looking at martial arts schools, you may wish to find out what level of sparring is used in classes. You may desire full-contact or limited contact for different reasons, for matters of comfort, learning, or something else.
At any rate sparring is a valuable part of Taekwondo and other martial arts training. It can add realism to your training, enabling you to see exactly how some techniques function. It can also provide benefits related to exercise, providing aerobics and strength training advantages as well.
