The idea of self-defense is the origin of Taekwondo. All defense and attack techniques, with arms and legs are real applicable in self-defense situations. The emphasis of Taekwondo lies in the leg techniques. In Taekwondo there are the most effective and most kicking variations of all martial arts.
Taekwondo training teaches the use of very efficient techniques for self-defense. Practicing the techniques in combat training strengthens self-confidence and helps to realistically assess a situation.
A potential attacker is looking for a victim. The prospect of a serious counterattack deters almost all attackers.