These are the geogaphical dimensions of the business.
Local is everything in neighbourhood – your city and region. This is a place you know the best – people, habits, history, local stories, beliefs, values, myths. You know where to go and to whom ask what. You know the opinion leaders and who is the authority. You know habits of local people and trends they are living up. Usually local you can reach within an hour or two drive.
National is further than local but still within your culture, language and history. This might be your country or if you live in a small country, this might include also your neighbouring countries within the same value system, life standard and mentality.
Global is the world. Everywhere where people speak different language, have different values, culture, beliefs and understanding of life. Going further away from your home requires more careful planning and you have to pay special attention to cultural differences.