Randomly from the top of my head, love is a not so easily describable feeling of emotions. I would go further to add that it should technically include 'respect' and trust. Different from lust which is does not include respect or trust but 'fueled' by pure desire..
What does Quran say? Fall not for the 'whisperings of Syaitan'...
In my opinion, it is a very well-written, balanced, and comprehensive piece of guidance for the Muslim Ummah. For example, an excerpt reads:
“In order to set the mood and atmosphere of romance, the wife should use various ways and means of seducing her husband. She may flirt, talk and behave amorously in order to arouse her husband’s sexual interest, avoiding anything that may be distasteful or a ‘turn off’. In this way, the scene will be set for a passionate and enjoyable session of husband-wife union, In sha’ Allah.” (p. 44)
To gain full benefit from the book, it is recommended that it be read in its entirety.
Both are valid within the context of marriage lol.
Love however, you can 'love' people for other than physical reasons even before marriage, you can desire people before marriage too obviously as Allah created us as creatures of desire, but you can only fulfill your desires in a halal manner within the context of marriage.
Love - Tender and passionate affection for another person. The implied meaning is that the liking of someone is within its rightful limits. In addition, if you start to feel love towards the opposite gender there is absolutely nothing wrong with that unless you wrongfully act upon it.
Lust - sexual appetite and desire. The implied meaning is any attempt to satisfy your feelings through any means other than marriage.