Any vector directed in two dimensions can be thought of as having two different components. The component of a single vector describes the influence of that vector in a given direction.
The Rh factor(the Rhesus factor or Rh antigen), is a protein that can be found on the surface of red blood cells. It is one of the most important blood group systems in human blood typing. The presence or absence of the Rh factor is denoted as either Rh-positive (+) or Rh-negative (-).
First learn basic HTML, then CSS and responsive CSS for Static websites and thereafter JavaScript and PHP for dynamic pages. If you also want to learn jQuery for more better works learn it at the same time with JavaScript