BoxSharer is a file sharing web application. What is File Sharing? File Sharing is the public or private sharing of computer data or space in a network with various levels of access privilege. While files can easily be shared outside a network (for example, simply by handing or mailing someone your file on a pen drive), the term file sharing almost always means sharing files in a network, like internet. File sharing allows a number of people to use the same file or file by some combination of being able to read or view it, write to or modify it, copy it, or print it. .