For a "mimi-introduction" to information theory, it's essentially how many little balls can fit inside a big ball. Each little ball is from a particular signal

For a "mimi-introduction" to information theory, it's essentially how many little balls can fit inside a big ball. Each little ball is from a particular signal as received with its errors in transmission, and the big ball is from the power of the signal. So, the number of little balls is how many different signals can send, with the assumed added noise level, and still have the signals all distinct at the receiver. So, sure, if send with more power have a larger big ball and more signals. Also if have lower noise, then signals are corrupted less, get smaller little balls, and can send more signals. Sorry, that's my best summary from the time I did look at information theory some years ago!!!