Every post type covered so far — posts, pages, a custom project type — has exactly two pieces of content: a title, and one big content area. That's genuinely enough for a blog post. It falls apart fast for a project that needs a client name, a completion date, and a gallery of images as separate, structured pieces of data rather than paragraphs mixed into one block of text.
A custom field is exactly what it sounds like: an extra, named piece of data attached to a post, alongside its title and content. WordPress has supported basic custom fields since very early versions, through a plain key/value box in the editor — functional, but with no field types, no validation, and a genuinely rough editing experience.
SCF (installed back in the setup lesson) replaces that with real, typed fields, organized into field groups that show up as a proper part of the editor screen — not a generic box at the bottom. A handful of the field types available:
| Field Type | Stores |
|---|---|
| Text / Textarea | A single line or paragraph of plain text |
| Number | A numeric value, with optional min/max/step validation |
| Image | A reference to a media library image, with its URL, alt text, and dimensions |
| True / False | A single checkbox — a yes/no toggle |
| Select | One choice from a predefined list |
| Link | A URL, paired with its own label and open-in-new-tab setting |
| Repeater | A repeatable set of sub-fields — rows an editor can add or remove freely (its own lesson ahead) |
A reminder from earlier
As covered in the setup lesson, SCF is the actively-maintained continuation of what most documentation and tutorials still call ACF (Advanced Custom Fields) — same function names, same underlying concepts, different plugin name after a 2024 licensing split.
The next lesson builds an actual field group and attaches it to the project post type from earlier, so every project gets its own client name, completion date, and gallery fields right in its editor screen.