DPI (Dots per inch) - measurement used for print resolution.
GIF (Graphics Interchange Format) - a bitmap image format that uses the lossless data compression technique to reduce the file size without degrading the visual quality.
GUI (graphical user interface) - a type of user interface which allows people to interact with electronic devices.
Linux - is a generic term referring to Unix-like computer operating systems based on the Linux kernel.
MySQL - a database management system which runs as a server providing multi-user access to a number of databases.
Source: Wikipedia.org, Dictionary