How is culture communicated?
Have you ever heard the phrase, "Monkey see, monkey do?" Although humans aren't monkeys, this phrase applies very well to our process of learning culture. Culture is kind of hard to define, but Anthropologists like to say that anything humans do that isn't biology (eating, drinking, sleeping, and reproducing) is culture. Culture is made up of language, food practices, art, beliefs about the world, styles of communication, architecture, bodily adornment, a collective history, gender and age roles, and so on. Culture may be communicated both implicitly and explicitly. As we grow up, we go through the process of enculturation, meaning we learn our culture from the people around us. Sometimes these cultural lessons may be very explicitly communicated, such as when a parent teaches a child table manners. Other times, it's quite implicit, like learning how to interact in a particular social situation based on observations of how others are behaving.
At any point in our lives, we may also experience acculturation on the micro or macro scale. Acculturation is a process were we learn another's culture. On the micro scale, if a friend teaches you how to make a traditional family dish, you're learning a part of your friend's culture. On the macro scale, an entire culture may learn something about another—consider the popularity of Mexican food in the United States. Acculturation is different from assimilation because it's not an active attempt to make one element of an "outside" culture fit neatly into a new, "inside" culture. Of course, assimilation involves learning a new culture through acculturation.
With that in mind, there's really very few things humans do that don't communicate culture because it makes up such a large, integral part of our lives. We create and re-create our culture through our actions, our speech, the food we eat, the homes we live in, and especially the media we engage with.