It describes the relationships that have always existed between the Father, Son and Holy Spirit from all eternity. God affirms the world with the energy of His self-affirmation. Because He not only loves but is Himself love, He has to be understood as the triune God. Love cannot be communicated by a solitary subject. If God is love He is at once the lover, the beloved and the love itself.
Love is the goodness that communicates itself from all eternity.
God's essence is to love. This love is outward looking. It is not something God can keep to himself within his own little family. He created humans in order to have someone with whom he could share that love. When humans rejected that love and turned to their own selfish and independent ways, as described in the first chapters of Genesis, then God did not give up on them.