What is the difference between a fragment shader and vertex shader? how do they relate?

vertex  shader is performed, while on each pixel,  fragment shader is achieved. The shader fragment is implemented after the implementation of shader vertex

Explanation:

A shader fragment is the same as a shader for pixels.

A major distinction is that a shader of the vertex can alter the vertices characteristics. whixch are the end points of polygon

On the other side, the fragment shader is responsible for the display of the pixels between the vertices. They are interpolated by particular guidelines between the specified vertices.

On each vertex, vertex  shader is performed, while on each pixel,  fragment shader is achieved. The shader fragment is implemented after the implementation of shader vertex