ex) 문단의 배경색을 지정하면 div는 직사각형 형태로 나타나고, span은 문장마다 길이가 다른 줄의 집합이 나타난다
#css
.js{
font-weight: bold;
color:red;
}
#first{
color:green;
}
span{
color:blue;
}
#html
<p>
<span id="first" class="js">JavaScript</span> (/ˈdʒɑːvəˌskrɪpt/[6]),
often abbreviated as JS, is a high-level, dynamic, weakly typed,
prototype-based, multi-paradigm, and interpreted programming language.
Alongside <span>HTML</span> and <span>CSS</span>,
<span class="js">JavaScript</span> is one of the three core
technologies of World Wide Web content production.
</p>