Most people are familiar with maple syrup, which is made from maple sap (Acer saccharum, mainly). But there are many other plants whose sap gives delicious syrups: birch, palm, and sugar cane, to name a few. Their properties and tastes may differ considerably from one to another.
Agave syrup (or nectar) comes from the salmiana agave (Agave salmiana). As its sweetening power is higher than that of sugar, much less of it is required.
Scented with real vanilla pods, agave nectar is an exotic delight.
Agave Nectar in Wikipedia.
Eight Facts about Agave Nectar in Fooducate blog.