box with text html code example

Example 1: html text box

<!-- A <textarea> tag (better for multi-line text)-->
<textarea cols="4" rows="5">
Some text inside the text box.  
See https://www.w3schools.com/tags/tag_textarea.asp
</textarea>

<!-- An <input> type text tag (better for single-line text) -->
<input type="text" value="Some text inside the text box">
<!-- See https://www.w3schools.com/tags/att_input_type_text.asp -->

<!-- Using contenteditable (not recommended) -->
<p contenteditable="true">Some text inside the text box</p>
<!-- See https://www.w3schools.com/tags/att_global_contenteditable.asp -->

Example 2: how do i make a boxin html

<div style="width:500px;height:100px;border:1px solid #000;">This is a rectangle!</div>

Example 3: how to style rule to apply the Border Box model css

header, ul, nav, li, a /* other elements */{

 display: block;
   -webkit-box-sizing: border-box;
   -moz-box-sizing: border-box;
   box-sizing: border-box;

Example 4: css box model

MDN (Mozilla Developer Network)
Probably the best place for an in-depth explanation of
web related technologies.

See the link below regarding the CSS BOX MODEL