What is a Class selector and how does it differ from an ID selector?

Question

I created "normal" table and all TD's have "border: 1px solid #e6e6e6" and "margin: 0". TR and TABLE have too "margin/padding: 0" but I still have space between TDs like here: h

Answer 1

The difference between an ID and a class is that an ID can be used to identify one element, whereas a class can be used to identify more than one.

We can also apply a selector to a specific HTML element by simply stating the HTML selector first, so p.jam { /* whatever */ } will only be applied to paragraph elements that have the class “jam”.

In the CSS, a class selector is a name preceded by a full stop (“.”) and an ID selector is a name preceded by a hash character (“#”).

So the CSS might look something like:

#top {
    background-color: #ccc;
    padding: 20px
}

.intro {
    color: red;
    font-weight: bold;
}

The HTML refers to the CSS by using the attributes id and class. It could look something like this:

<div id="top">

<h1>Chocolate curry</h1>

<p class="intro">This is my recipe for making curry purely with chocolate</p>

<p class="intro">Mmm mm mmmmm</p>

</div>