It uses SSH and Apache modules and Linux has its own mail client servers, far from the simple standardized Microsoft mail program, Outlook or Outlook Express. Linux consists of the kernel, system library and system utility. , hardware and hull. The kernel is the central part of Linux. The kernel consists of various modules and interacts directly with the hardware to provide process control, networking, access to devices and file systems. He is responsible for all major activities of the system. Most Linux drivers such as its print server, CUPS and the Xorg graphics server are generally part of the kernel. Xorg is an implementation of the X Windows system developed by MIT in 1984 that provides services based on demand from clients running from the server locally or remotely. It manages input devices and the display of colors and fonts by communicating over the network via the X protocol, a network protocol capable of executing