They are usually used in the content for pages and posts. If you’re in the visual mode of the post editor, shortcodes are usually replaced with a preview of the content they will display on the site. If you’re using the text mode of the post editor, you can see the shortcodes in the content.
One of the most commonly used shortcodes is the gallery shortcode, which usually looks something like this:
[gallery id="123" columns="3" size="large"]
This shortcode will load the gallery with ID 123, and display the images in the “large” image size and three columns. You can create a gallery by clicking the “Add Media” button, clicking the “Gallery” tab on the left, selecting multiple images and clicking the “Create a New Gallery” button. This will insert a shortcode with the images and settings you selected to your content.
WordPress includes the following shortcodes out of the box:
Additional shortcodes can be added by your active themes and plugins.