Simplest way to mount a LCD flat panel display screen is onto a vertical wall with a Vesa mount consisting of two metal plates with holes in them. One plate is screwed to the wall and the other bolted to the back of the display panel (there are standard spaced threads on the back of most display panels for this). The two plates maybe joined by pivot, so the screen angle can be changed slightly.
However, there is occasionally a need for mounting a screen from the ceiling, floor mounting or having a screen on a mobile stand. For this there is a bewildering range of screen mounts. But these can cost thousands of dollars. The simple two plate VESA mounts are available for less than $100.