WTF school. Teaches Kibon Il Jang- Taegeuk Pal Jang. Koryo for black belt
To clarify Dirty Dog's post, which is correct but IMO slightly pedantic.... the World Taekwondo Federation is actually the sports organization that oversees Taekwondo competition, while Kukkiwon ("The World Taekwondo Headquarters") is the governing body for this style of Taekwondo. My understanding is that, because Kukkiwon is part of the Korean government, they can't be the world governing body for the
sport of Taekwondo for geopolitical reasons. So they started the WTF to handle that end of things, and the WTF is now more famous than Kukkiwon, so schools tend to use that name to describe their style of Taekwondo instead. But when you get your black belt, the certificate will say it's from Kukkiwon and have the KKW President's signature on it.
Anyway, that aside......
Let me give you two examples from Taekgeuk Pahl-Jang.
Think about the "middle line" of the form, where you do a front kick to the left and right. The tiger stance loads all your weight on the back leg and has your front leg just touching the ground, which allows you to snap out a kick with that front leg very fast. Then, you drop into a front stance in order to close the distance between you and your opponent and get into punching range. Then, after punching them, you retreat back into tiger stance to block their imaginary counterattack.
Now, think about the "bottom line" of the form. You block your opponent's strike while in a back stance, which gives you a very narrow profile. Then, after you block, you grab your opponent with your open hand and shift over into a front stance, which gives you the stability to pull them in and give them an elbow strike-backfist-punch right in the face.