A briefcase and attache case are similar but not the same. An attache case is a traditional hard-sided square case. A briefcase can resemble an attache case, but are also often soft sided, expandable, and bag-like, i.e. briefbags. Hard-sided briefcase has a strong, durable, and rigid frame that provides excellent security and safety. Compared to a soft sided one which is more lightweight and portable, and will expand to accommodate greater storage needs. If you plan to buy a briefcase or attache case for carrying a laptop computer, check your laptop's dimensions first to make sure that it will fit inside (screen size is measured diagonally). Full grain leather briefcases will age better than cheaper leather ones. Aluminum and ballistic nylon are modern materials designed for endurance and resiliency. A modern briefcase doesn't have to be case-like. Expandable briefcases and briefbags offer enhanced carrying room for files and electronic devices. Their designs are more casual and well-suited to frequent business travelers.