Messages contain information and redundancy
There are two parts to a signal conveying a message: information and redundancy. Information we all know about. It‰s the stuff knowledge is made of.
Redundancy is that part of the signal that increases the the chanced for being understood
There is a trade-off here. The more redundancy there is in a message, the less information is transmitted, but the chances of being understood are improved.
On the other hand, if there is much information, the chanced of having it understood are decreased.