It is not easy to define what love is, at least not in a literal sense. This is partly because love is of the unlimited and can therefore not be defined very well. Trying to define love too precisely is like trying to put limits on the unlimited. But speaking in a more poetic sense, we could perhaps say, love is a bit like light and warmth, like the energy from the sun. It includes a warm feeling and it also includes the energy for intelligent perception.
Love is a feeling that can be sensed, but it's of course more than just that.
On a biological level we could think of it in terms of hormones. If love can be sensed then there must be some kind of hormone that is producing the feeling. Something liberates the hormone, which produces the feeling. This energy liberates the hormones harmoniously and this is sensed as love. The sense of love also energizes the intention and will to do something.