When editing product descriptions, collection descriptions, page content or blog post content, you sometimes may find it helpful to view the raw HTML code for the page.
Additionally, if you're looking to add in any code into these pages (third-party app widget, column framework code etc.) you'll need to switch to code view in order to add it properly!
The "code view" button is a "toggle"-style button at the top of the content editor for product descriptions, collection descriptions, page content and blog posts.
Step 1: From the Shopify Admin, navigate to your page/product/collection/blog post.
Step 2: In the upper right corner of the rich text editor is an icon that looks like this <>.
Clicking this <> button once will change to code view. You can click it again, while in code view, to return to the visual editor view.
Note that there will, in most cases, be more content in the code view that is not visible or is shown differently in the regular view.