Valongo's famous biscuits can be found in different shapes and flavours. “Valongo Biscuits”, as they are known, are increasingly sold throughout Portugal.
And they offer a little something for everyone: maize, lemon, twists, digestives, cacos (thins, known as French biscuits), fidalguinhos, and some others that are created to please customers.
Here's the difference between biscuit and cracker: the word biscuit is older, but they are synonyms.
These were cooked several times to remove moisture and delay decomposition. It was one of the food stuffs stocked on ships that spent several months at sea. They weren’t sweet at first, and only later became treats.
Crackers are drier and have a flattened shape, you could say that all crackers are biscuits, but not all biscuits are crackers... Biscuits were too expensive for most people, which is how the raleiro appeared - an assortment of pieces broken off biscuits as they came out of the oven, which were sold cheaper pound for pound.
In 1712, Father Raphael Bluteau defined biscuit:
“Bifcouto”. A gluttonous treat. “Bifcoutos” are made in many ways. There are apple biscuits, made with flour, cow butter, sugar, eggs, etc. The size of a finger, or little rings, &c. “Bifcoutos” de ovos, “Bifcoutos” de nata, “Bifcoutos” de la reina, &c. Vid Arte da Tom. 2