Being "in love" is an altered state. Your focus is on your partner and you can't bare being without that person. You are in a bubbly state of a desiring feeling to want them in your life. You look beyond the present and start looking towards the future.
However to have Love for another person, in contrast is closer to appreciation and affection. However you don't feel that needing when separated you care about them in which you don't want anything bad to happen to them. Your not in that bubbly state
To love is; to cherish, to be kind to, to want to spend time with, to respect, to enjoy, to trust, to want to know better.
To be in love; to be smitten, infatuated, enamored, hooked, taken with, besotted, head over heels.
When you are in-love, you think of them constantly, enjoy their company whether you're talking or not, just being in the same room together is comfortable and pleasing, you appreciate and respect them and the differences between the two of you, you cannot imagine your life without them in it, every day you feel your heart could not possibly love them more until the next day when the love in your heart grows yet again for this person. Being in-love, is a strong passionate emotion powerful enough to prompt great changes in your life. It can also heighten your sexuality in that you want to be so completely wrapped up with this person you have an intense desire to show your love physically, unselfishly pleasing them completely before yourself because when you're pleasing them it gives you a heightened sense of pleasure within your soul.