4. Block-level vs Inline

Now that we’ve gotten familiar with what elements are in HTML, let’s talk about the two categories that every element in HTML can fall into. Block-level and inline-level elements in HTML both serve different purposes when it comes to structuring web content. It is important that we understand their differences.

The Two Categories

Block-level elements create an invisible “block” or rectangular box in the document. They typically start on a new line and extend the full width available within their containing element (usually a parent block-level element).

Inline elements, on the other hand, flow with the content and do not start on new lines. They only take up as much width as necessary for their content. This means that if the content is small, the inline element will also be small. Also, inline elements can be put side by side next to each other without needing to use any CSS tricks. Block-level elements require the usage of float for this.

Here’s an image demonstrating Block-level & Inline-level elements:

Here’s an in-depth look at their main characteristics and differences:

Block-Level Elements:

1. Structure and Layout: Block-level elements create an invisible “block” or rectangular box in the document flow. They typically start on a new line and extend the full width available within their containing element (usually a parent block-level element).
2. Semantics: Block-level elements are used for defining the structure and hierarchy of a web page’s content. They often represent major sections or divisions of a page, such as headings, paragraphs, lists, and divisions (<div>).
3. Examples: Common block-level elements include <div>, <p>, <h1> to <h6> (headings), <ul> (unordered lists), <ol> (ordered lists), <li> (list items), <table>, <form>, and others.
4. Nesting: Block-level elements can contain other block-level and inline-level elements, making them versatile for structuring complex layouts.
5. Styling: Block-level elements are typically affected by CSS properties like width, height, margin, and padding. You can control their layout, positioning, and spacing.
6. Default Behavior: Block-level elements usually start on a new line, stacking vertically by default. This can be altered with CSS properties like float or display.

Inline-Level Elements:

1. Structure and Layout: Inline-level elements flow within the content of a block-level element. They do not start on new lines and only take up as much width as necessary for their content. If the element’s content is a single word, for instance, that will be the element’s width.
2. Semantics: Inline-level elements are used to style or modify specific parts of the content. They don’t define the page’s structure but rather provide additional information or formatting within the content.
3. Examples: Common inline-level elements include <span>, <a> (links), <strong> (strong emphasis), <em> (emphasized text), <abbr> (abbreviations), <img> (images), <br> (line breaks), <i> (italic text), and others.
4. Nesting: Inline-level elements can be nested within other inline-level elements and sometimes within block-level elements.
5. Styling: Inline-level elements are typically affected by CSS properties like font-size, color, text-decoration, and font-weight. They are useful for text-level styling. However, they are not affected by properties such as margin and padding.
6. Default Behavior: Inline-level elements do not start on new lines and flow horizontally within their parent element. They stack side by side to each other along with their content.

<div class="container">
  <div class="inner-text">This is a block level element
    <a href="#">This is an in-line level element</a> <a href="#">Another in-line level element</a>
  </div>
</div>

In summary, block-level elements are primarily used for structuring and defining the layout of web content, creating distinct blocks of content that typically stack vertically. Inline-level elements, on the other hand, are used for styling and modifying specific portions of text or content within block-level elements. They stack horizontally.

Understanding the differences between these two types of elements is crucial for effectively structuring and styling a document.