Pleasure activates a brain region that is also stimulated by other pleasurable experiences, such as good food. Love, on the other hand, activates the reward center in the brain, which is also closely linked to habits and addictions.
Both of these areas respond to sensory perception. Love and lust have differences, but also striking similarities in the brain.
Ultimately, love is nothing more than a kind of addiction. Similar to drug addiction, it is a habit that is fulfilled through satisfaction develop desire. They activate all those processes in the brain that are responsible for pair bonding.
All in all, the processes in the brain when it comes to love are a lot more abstract and complex than when it comes to pleasure, which primarily occurs when the person in question is present. Love, on the other hand, can also be felt when the partner is absent.