The main differences between display: inline, block, and inline-block in HTML/CSS are layout behavior, space usage, and styling control. 1. Inline elements flow with text, don’t start on new lines, ignore width/height, and only apply horizontal padding/margins — ideal for inline text styling. 2. Block elements take full width, start on new lines, respect all dimensions, and stack vertically — used for major structural components. 3. Inline-block elements sit inline like text but allow full size control, making them ideal for horizontal layouts like navigation bars, though whitespace in HTML can create gaps between them.

When you're working with HTML and CSS, understanding how elements are displayed on the page is key to laying things out right. The main difference between display: inline, display: block, and display: inline-block comes down to how each behaves in terms of layout — specifically, how they take up space and interact with other elements around them.

Let’s break it down based on what you’ll actually run into when building layouts.

display: inline – Goes with the flow

Elements set to inline behave like text. They sit inside a line of content and don’t start on a new line. You’ll notice this with tags like <span></span> or <a></a>, which are inline by default.

• They only take up as much width as their content needs.
• You can’t set a specific width or height — those styles will be ignored.
• Padding and margins work horizontally (left/right), but vertical ones (top/bottom) won’t push other elements away the way you might expect.

Use case: When you want to style part of a sentence or line without breaking the flow — like highlighting certain words or adding small icons inline with text.

display: block – Takes the stage alone

Block-level elements take up the full width available and always start on a new line. Think of elements like <div>, <code><p></p>, or <h1></h1> — they stack vertically by default.

• They respect width, height, padding, and margin in all directions.
• If you put two block elements next to each other in HTML, they’ll appear one after another, not side by side.
• Each block element acts like its own box that separates itself from surrounding content.

Use case: For larger structural pieces — sections, paragraphs, buttons that need room to breathe — where you don’t want anything else sitting beside it.

display: inline-block – The best of both worlds?

This one’s handy when you want something block-like but still flowing within a line. An inline-block element sits inline (like text), but you can control its size and spacing like a block.

• It doesn’t force a new line, so it can sit next to other inline or inline-block elements.
• Width, height, padding, and margins all work as expected.
• One thing to watch: since it behaves like text, whitespace in your HTML can create small gaps between inline-block elements — like buttons in a toolbar.

Use case: Creating horizontal lists, grids, or UI components that need consistent spacing and sizing while staying inline — think navigation bars or sets of icons.

Here's a quick comparison:

• inline: flows like text, no width/height control
• block: starts new line, full width, full control over size
• inline-block: stays inline, allows full size control

One detail worth noting: if you're trying to line up several inline-block elements and there's an unexpected gap between them, check your HTML spacing. Even a simple line break or space between elements in the code can show up visually. You can fix that by setting margin-right: -4px or using HTML comments to eliminate whitespace.

Another thing — sometimes people try to center inline-block elements inside a container using text-align: center. That works fine, but remember that text-align affects all inline content inside the container, not just the inline-block ones.

So yeah, choosing between inline, block, and inline-block really depends on how you want the element to fit into the page flow and what kind of control you need over its dimensions and positioning. It’s not complicated once you see how each behaves in practice, but it’s easy to overlook small quirks like spacing issues or ignored styles if you’re not paying attention.