The Linux framebuffer (fbdev) is a graphic hardware-independent abstraction layer

Abstraction layer

An abstraction layer is a way of hiding the implementation details of a particular set of functionality...

 to show graphics

Computer graphics

Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....

 on a computer monitor, typically on the console. The word framebuffer

Framebuffer

A framebuffer is a video output device that drives a video display from a memory buffer containing a complete frame of data.The information in the memory buffer typically consists of color values for every pixel on the screen...

means a part of video memory

Video memory

Video memory is a term generally used in computers to describe some form of writable memory, usually RAM, dedicated to the purpose of holding the information necessary for a graphics card to drive a display device...

 containing a current video frame, and the Linux framebuffer means “access method to the framebuffer under the Linux kernel

Linux kernel

The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....

”, without relying on system-specific libraries such as SVGALib

SVGALib

SVGAlib is an open-source low-level graphics library which runs on Linux and FreeBSD and allows programs to change video mode and display full-screen graphics. Some popular games like Quake and Doom used it in their original releases....

 or another user space

User space

A conventional computer operating system usually segregates virtual memory into kernel space and user space. Kernel space is strictly reserved for running the kernel, kernel extensions, and most device drivers...

 software.
There are three applications of the Linux framebuffer.

• An implementation of text Linux console
  Linux console
  The Linux console is a system console support in the Linux kernel. The Linux console was the first functionality of the kernel, developed as early as in 1991 . On PC architecture, it is common to use VGA-compatible video hardware. Implementations of computer graphics on Linux are excluded from the...
  
   that doesn't use hardware text mode
  Text mode
  Text mode is a kind of computer display mode in which the content of the screen is internally represented in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of character cells, each of which contains one of the characters of a...
  
   (useful when that mode is unavailable, or to overcome its restrictions on glyph size, number of code points etc.).