Who is the Giver?
In Jonas' community the Giver is an elder who gives the council guidance on all decisions in the community. He is an elderly man, but not as old as he looks. He has some magical abilities so that he can transfere memories.
When he was a 12 he was chosen to becomeThe Receiver of Memory. This process was how the community held its memories, "and back and back and back"... After he grew older and was weakened from the stress of his responsibilities to the community another 12 was chosen to replace him. The first 12 that the council chose didn't work out and Jonas is the 12 now selected to become the Receiver of Memory. The elder who is now the Receiver becomes the "Giver." It will be up to him to transfer memories, guide, and teach Jonas to replace him. He was the giver of advice and he is the "Giver" of memories for Jonas, the new "Receiver of Memories.
The Giver is an elder in Jonas' society that holds and then "gives" memories of aspects of life that the society has eradicated to Jonas, like sorrow, colors, pain, fear, and love. Jonas comes of age and is placed in the position of becoming the new Receiver of Memories. The old Receiver in turn becomes known as "The Giver" and shares these memories with Jonas. The society has chosen the Giver, and then Jonas, in order to have someone hold the memories in case the society ever needs to refer to them, and also to keep the society safe from the pain of these memories. Jonas soon comes to learn that the memories the Giver gives him open him to the possibilities of what once was and could be again. The memories change his perspective on life and shatters his illusions of the society he lives in.