What is the role and responsibility of HTML, CSS and JavaScript technologies when creating the front end?


With these three technologies HTML, CSS and JavaScript can be developed all front-end or client-side of a particular site.

So, I would like to know what role and responsibility each of these technologies mentioned above plays in creating the front-end of a particular site and what are the differences between them in relation to one with the other?

asked by anonymous 17.04.2016 / 18:36

1 answer



HTML - Setting up the elements

CSS - Stylize display of elements

JS - Element logic and dynamics

In a practical example, if I want to have a blue square that has a count of seconds from 1 to 50. For this, I would first name the square in the HTML, then I would say that it has the square shape and the blue color in the CSS and would do the number counting logic in Javascript. For example, we have:

var meuQuadrado = document.getElementById("meu-quadrado");
var contagem = 0
var repeticao = setInterval(function(){ //loop da contagem
  if(contagem == 100){ //se a contagem chegar a 100
    clearInterval(repeticao); //pára a contagem
  meuQuadrado.innerHTML = contagem; //exibo a contagem dentro do quadrado
  contagem++;  //aumenta a contagem
/* CSS */
  color: white; /*cor da fonte */
  font-size: 170px; /* tamanho do texto */
  text-align: center; /* posição do texto */
  background-color: blue;  /* cor do fundo */
  width: 200px; /* largura */
  height: 200px; /* altura */
<!-- HTML -->
<div id="meu-quadrado"></div>
17.04.2016 / 18:49