Scanning is the method of finding out something about a person through his/her sura/ energy signature, everyone and everything in the world has a unique energy signature which can be used to identify the/thing it belongs to.
To scan a person you have to form a link with them, to do this, relax and feel the energy surrounding you, move it around a bit and get comfortable, then when you are feeling comfortable enough, send out your energy to the aura of the person who you want to scan and visualize it forming a rope of energy, when you do it right you will get a feeling, i cant explain the feeling, to me its like a pulling sensation all over my body. Once you have formed the link, just look for the information you want to know about the person, it will take some time at first but after a while you will be able to scan people in just a few minutes.
Scanning can be done only when the person you are scanning allows it or if the person doesnt sense the link, it is easy for a person to remove the link if he/she senses it. Scanning can be used to learn about the spiritual energy of a person, also if the person has a energy block or some illness, it can also be used to find out something the person has suppressed or forgotten or even a dream they had.