A file uploading service won't allow two files with the same file name to be uploaded. If a file name already exists, it will ask the user to change the file name.
a) Describe with examples how abstraction can help decide how to compare the files.

William travels a lot on business purpose. he needs to regularly communicate with his business partner. he also needs to send out weekly reports to his boss while he is traveling. which web-based application best suits william’s needs? (social media, webmail, wiki) is the best web-based application for william. he can access this application via the internet using a (digital cable, fax machine, web browser).