Reality is not exactly as it appears in the land of Faerinet (fair-i-nay). Obstacles exist only by way of a very powerful spell using ancient magic, and they could be anything from a tree to a statue. In order to bypass these obstacles, Link must jump to the Realm of Secrets where they don't exist because the spell doesn't apply there.
Farore, the Oracle of Secrets, is the descendant of a long line of women with the power to jump to and from the Realm of Secrets. Jarok seized Farore, and forced her to lead him to the Realm of Secrets allowing him to awaken the Arcane Army which had been sealed there for centuries. He then uses the army to spread warfare throughout the land of Faeranet in order to light the Flame of Strife.