A code is a set of symbols that are joined to create a meaningful message. For communication to take place, the participants must share the code to encode and decode messages. Encoding is the process of mentally constructing a message. Decoding is the process of interpreting and assigning meaning to a message. If the relational partners are using the same code, they are more likely to encode and decode messages accurately and arrive at the shared meaning they want to communicate.

Speaking a common language is the most obvious example of sharing a communication code, though it is certainly not the only one. Baseball teams, for example, develop elaborate codes for various pitches and plays, which players communicate through hand gestures and body movements (for example, by removing a baseball cap, holding up three fingers, and shaking them twice). Similarly, consider the emoticons and texting and chat-room shorthand we use when communicating online—especially when we’re in a hurry.