Human communication, namely, human language, has six unique traits which establish the huge contrast between our system of communication and the systems of communication among animals and other creatures. Although all living beings communicate in their unique way, what sets the human system aside is precisely those six unique properties. The properties that are explained below are listed in no order of importance, as they are all equally necessary to the process of language, communication, and understanding.
The first trait to consider is productivity. This entails that our language serves a purpose. Its purpose is to produce communication and emit messages that will be used for further tasks. Although most living beings produce their own communication for their own common needs, human language is unique in that it comes in both written and oral form and both serve the same goal.
The creativity trait confers our language the ability to ply the already established norms of grammar, morphology and syntax into new words, complete with new semantic goals. For example, whenever a rock star or someone famous coins a new word, such word is accepted and even used globally.
Displacement is used in human communication to describe or refer to things that are not visually present. Yet, the fact that their names are mentioned adds to the validity of human productivity. Babies are often taught displacement when they are asked questions such as "Where is grandma?" even when grandma is not in the room. Using this property shows that words are still valid with or without visual support.
The arbitrariness property is perhaps the most interesting because we often take it for granted. It entails the fact that written words and spoken words do not necessarily have to correlate in terms of sound and symbol. We can write a word and pronounce it completely different. Some great examples that often come up in Linguistics exercises are the provinces and estates of England. When you have names of towns such as Warwick, Berwick, and Alnwick, the first tendency is to pronounce each sound that is written down as you read it. However, neither of those towns are pronounced in modern English and, actually, the letter "W" is meant to be silent. Hence, their actual pronunciation is "warick", "berrick", and Alnwick is even more unique, as it is pronounced "anneck". That is the beauty of arbitrariness.
The property of duality refers to the fact that words can be broken apart into chunks. Those chunks may or may not have a meaning, however, they are extremely useful to form new words. A wonderful example of such important word chunks are suffixes and prefixes. Although the lexemes, themselves, do not seem to have meaning, when they are attached to a word they affect the meaning of that word, altogether. Hence, not every part of a word has to make sense on its own. That is the duality of it.
Finally discreetness sort of reaffirms duality as it establishes the fact that words are a combination of sounds and symbols, and the symbols are letters and syllables. Again, the syllables may have no meaning on their own, but they are indeed identifiable as imperative in the process of word formation. Even though they do not seem important, they are recognized as being so.
Therefore, these properties make our human language as eclectic, colorful, flexible and malleable as one can imagine. They are also what make our communication so unique.