Creme de Banane is one of their classic liqueurs, this with banana flavors. The "creme" indicates that it will have a higher sugar content than other liqueurs and appeal to sweeter palates. They say it has "intense flavor" and meant to call to mind the "luxuriance of a far off climate."
Giffard is a French company specializing in a wide variety of liqueurs and eua-de-vie among other products. Some of those extra products are flavored cocktail syrups (or "sirop"). They are generally sweetened with pure cane sugar.