Culture is the product of a society living according to their worldview. It includes values, social structures, and creative expressions. Everyone has a culture, but many people identify primarily with a sub-set of the culture in which they find themselves.
In Genesis 11 and Revelation 7, we see that God values a diversity of human cultures. He loves to be worshipped in multiple languages and and through the art, work, and festivities of the different peoples of the earth.
Some cultures are very similar to one another. Their shared language and geographic proximity have resulted in the Colombian and Venezuelan cultures having much in common. The cultures of Colombia and, say, Cambodia, on the other hand, are very different from one another. This is called "cultural distance." When people are culturally distant, there are many barriers that much be overcome in order for people of one culture to influence the people of a distant culture.