jekyll/docs/_docs/step-by-step/02-liquid.md

layout	title	position
step	Liquid	2

Liquid is where Jekyll starts to get more interesting. Liquid is a templating language which has three main parts: objects, tags and filters.

Objects

Objects tell Liquid where to output content. They're denoted by double curly braces: {% raw %}{{{% endraw %} and {% raw %}}}{% endraw %}. For example:

{% raw %}

{{ page.title }}

{% endraw %}

Outputs a variable called page.title on the page.

Tags

Tags create the logic and control flow for templates. They are denoted by curly braces and percent signs: {% raw %}{%{% endraw %} and {% raw %}%}{% endraw %}. For example:

{% raw %}

{% if page.show_sidebar %}
  <div class="sidebar">
    sidebar content
  </div>
{% endif %}

{% endraw %}

Outputs the sidebar if page.show_sidebar is true. You can learn more about the tags available to Jekyll here.

Filters

Filters change the output of a Liquid object. They are used within an output and are separated by a |. For example:

{% raw %}

{{ "hi" | capitalize }}

{% endraw %}

Outputs Hi. You can learn more about the filters available to Jekyll here.

Use Liquid

Now it's your turn, change the Hello World! on your page to output as lowercase:

{% raw %}

...
<h1>{{ "Hello World!" | downcase }}</h1>
...

{% endraw %}

It may not seem like it now, but much of Jekyll's power comes from combining Liquid with other features. Let's keep going.