The genre of Romantic Fiction has two strict criteria: The first is that the story must focus on the relationship and romantic love between two people. Secondly, the end of the story must be positive, leaving the reader believing that the protagonists' love and relationship will endure for the rest of their lives.
Romance is that aura that surrounds falling/being in love. It's that light-headed, stomach dropping, lump-in-your-throat feeling you get when the man you love says something sweet, does something silly that touches your heart. It's the excitement of the chase and the capture. . . and later the eternal imprisonment of your heart.
One definition of Romantic Fiction is that romances are our modern fairy tale. A romance is a work in which the plot centers around a love relationship and draws its power from the feeling that falling in love is one of the defining moments of our lives: if it culminates in marriage and a family, it is an event that affects the future as well as the present.