to write the sequence. If we know English quite well, we will need much less information to write the sequence. For example, for the last character of the sentence "I love yo_", you may need no information to guess the underscore is "u" if you know English, but I need information log (26) bits to guess the character if I do not know English except 26 letters. Even though the distribution of each English letter is actually not equal at all, but I do not know the probabilities of each letter, I have to assume equal probability. I still need information log(26) bits for each character. Different persons need different information to know because they know differently. Information is the difference between the entropy of known and unknown. How much information you need depends on how much you have known, therefore depends on the entropy of unknown. The more you know, the less the entropy of unknown, and the less the information you need. For a sequence, we can also say the information of the sequence is the information we need to write the sequence.