Cultural conexions between Spain and Portugal are quite close. Both countries are Iberian and they used to be a single country in large periods of history.
Portuguese and Spanish are two language so close related two persons can talk each other one in Portuguese and the other in Spanish without loosing so much of the meaning. If a spanish speaker wants to SPEAK portuguese requires training, but for listening or reading Portuguese no trainning is requiered.
Now, Portugal and Spain are not identical. People, traditions, sensibility and arts are similar but not exactly the same. Spanish Flamenco is rude and violent, Portuguese Fado is all sweetness. Spaniards bullfighting is a ritual killing of a bull; Portuguese one is a gymnastic show without the butchery. Spaniards love tragedy, Portugueses preffer fun. But they also share many things in common. Both love wine and are Latin societies.
The same is true between Hispanic America and Brazil, which are related peoples but not exactly the same.
Pinguin