Realm of Supreme Truth. See Khands. Sach Khand is nothing but the transformed Sat Hirda. Sach Khand is the Hirda in which Truth, God, appears and fills it up with all of the super infinite divine qualities and powers. At that stage there remains no difference between God Himself and the soul that has become Sat. This soul merges with the Nirgun Saroop of Akal Purakh, which is the Sat and the Origin of the creation. When this divine merger happens then no doubts remain and there is no more separation. God and the soul become one and there remains no difference between the soul and God Himself. This is a divine event and is called meeting with Akal Purakh. Therefore, the key to success is become a Sat Hirda, which can be achieved by focusing on Sat and Sat Naam Simran.