There are many different kinds of love. There is the love of a parent for a child, the love of an animal owner for their pet, the love of a child for a parent, and that changing love of an adult child for an ageing parent. There is also, of course, the love of one adult for another in the romantic sense.
There is a great deal of literature on "love". You will find many poems and many other writings.
A selection is easily found:
"Love gives naught but itself and takes naught but from itself. Love possesses not nor would it be possessed; For love is sufficient unto love." Kalil Gibran
"How do I love thee? Let me count the ways./ I love thee to the depth and breadth and height / My soul can reach, when feeling out of sight / For the ends of Being and ideal Grace." Elizabeth Barrett Browning
"Love is a breach in the walls, a broken gate, /Where that comes in that shall not go again;" Rupert Brook
LOVE - what is love? A great and aching heart; /Wrung hands; and silence; and a long despair. Robert Louis Stevenson
Of course, if you are looking for the scientific explanation, that is available too at several places, just do a search on "scientific explanation love"