As a symbol, the library operates on a few different planes in the film. It represents Andy's relentlessness, society's dismissiveness of the inmates, and, as all libraries are, an entrance to a world beyond one's own borders. Expanding the library is Andy's pet project for all those reasons. It's an "in yo' face" to the State of Maine, who won't spend a few bucks on something that might actually help the prisoners; it's something to keep himself occupied while he makes his longer-term plans; and it's a gift to his fellow prisoners, most of whom haven't had the opportunities for education that Andy had. It's a place of safety apart from the cell block, where Andy can be himself with his books and accounts.