Would you please explain in detail the relation between Bhakti and Love?

Bhakti means love of God or as Srila Prabhupada would often translate the word, pure devotional service to God. (The Sanskrit root of the word bhakti is bhaj, which means loving service). Because Krishna is the origin of everything, He is the origin of love also.

There is much more to loving Krishna than just saying, to love God. We attain pure love for Krishna through a gradual process that takes us through progressively higher realms of Bhakti. The three progressive stages are: (1) regulated practice, (2) attachment, and finally (3) pure love. Fortunately, we can begin the process at any point in life or wherever we are in our spiritual journey.

The Bhakti process is systematic and is laid out in detail by the followers of Sri Chaitanya in books such as Bhakti-rasamrita-sindhu (presented by Srila Prabhupada as The Nectar of Devotion). These books provide not only instructions but also guideposts by which the student of Bhakti can evaluate his or her progress.