Spanish is an international language spoken in over twenty countries including the USA. This means that there are many interesting differences in regional usage. Contrary to what is often assumed, it is not just a question of Peninsular Spanish vs Latin American Spanish. It is much more complicated than that. Let's look at a few examples.
bus This word has one universally accepted Spanish equivalent and some others which may cause confusion.
Universal: autobús
Central America and Mexico: camión
Argentina and Venezuela: colectivo
Peru and Uruguay: ómnibus
Chile: micro
Canary Islands and Cuba: guagua
The translations above can mean different things according to region, so:
camión means a truck or lorry throughout the Spanish-speaking world including Central America and Mexico. If you want to be completely unambiguous in Central America and Mexico, call a truck a camión de carga.
colectivo in several Latin American countries is a car which picks up and drops off fares along a set route.
micro in many Spanish-speaking countries is a mini-bus.
guagua in Andean countries is a colloquial word for baby.
lunch: In Spain and most of Latin America almuerzo means lunch. In Latin America it is the standard word for lunch, but in Mexico it means a mid-morning snack, whereas in Spain almuerzo has connotations of a formal lunch. Comida is the preferred standard word for lunch in Spain and Mexico.
coger Visitors to Spain will hear this word constantly. It has several meanings such as to take (a taxi, a bus, a pencil), to pick (flowers, fruit), to catch (a ball, a thief, a cold), to go down (a street) and several more besides. However, outside the Peninsula it is probably best to forget its existence altogether. This is because in Argentina, Mexico, Paraguay, Uruguay and Venezuela it is the equivalent of the four-letter F-word in English. Even in the other Latin American countries, its use is shunned. The solution is to use uncontroversial verbs like tomar, agarrar, atrapar, and thereby save some hilarity and a few blushes.
Fortunately, help is at hand in the shape of the Oxford Spanish Dictionary, which rigorously discriminates regional usage and is due for publication next Spring.