To continue, it is important to discuss some terms that are related to communication and highlight difference between them.
Signal vs. message
In everyday language we use these terms almost interchangeably, but they have specific meanings in the theory of communication.
- Message — it is semantic content, that has some meaning at least for the sender.
- Signal — it is technical or environmental means to transfer the message.
For example, message can be “I’m hungry” but the signal can be a spoken phrase in English or German, or text, or some indicator that turns on once the sender pressed some button.
So, we can consider that the message is the conceptual idea, and the signal is representation of the message in some form and format that can be received and decoded by receiver.
Data vs. information
Again, these words are often confused in daily conversations, but they have very different meanings in, for example, information theory.
- Data — raw numbers, digits, symbols that are not processed and interpreted. For example, data base with all temperature sensor readings stores the raw data.
- Information — processed, interpreted data, that now has some semantical meaning. For instance, the data from temperature sensor is processed into information like “It is cold right now and it was even colder before”.