change font of html and font suize code example

Example 1: html font size

<span style="font-size:20px;"></span>

Example 2: how to increaase font size on html

<font size="+2">This is bigger text.</font>

Example 3: how to change the font in html

<script>//for typewriter font:</script>

<tt>
  <h1>Example Text</h1
</tt>