Debian-based systems such as Ubuntu and RedHat-based systems such as CentOS are mostly similar in their design. However, there are a few differences here and there. For example, RedHat-based systems use .rpm files for representing software packages, while Debian-based systems use .deb files. These file types differ from one another in their design, and cannot be installed outside of their respective type of operating systems (e.g. installing a .deb file on CentOS, or installing a .rpm file on Ubuntu). However, there are ways to port these packages to other types of systems.