In website terminology, a theme is a packaged set of design and code files that controls how a site looks and how its pages are structured. A template is typically a single layout within a theme, defining the structure of a specific type of page (homepage, blog post, product page, contact page).

The terms overlap in usage: many platforms use “template” loosely to mean what other platforms call a “theme.”

How themes and templates relate

A typical CMS theme consists of:

Templates, files that define the layout of specific page types (e.g., home.html, post.html, archive.html)
Stylesheets (CSS), the visual design (colors, typography, spacing, layout)
JavaScript, interactive behavior
Images and assets, logos, icons, background images
Configuration, theme options exposed to users (color schemes, layout choices)

A site uses one theme at a time. Within that theme, different page types use different templates.

Themes by platform

Platform	Term used	Customization model
WordPress	Theme	PHP templates + CSS, via theme files; child themes for safe customization
Shopify	Theme	Liquid templates + CSS; theme settings in admin
Squarespace	Template (older) / Brine family / Fluid Engine (newer)	Limited customization through theme options
Wix	Template (starting point); ongoing edits via editor	Fully visual, less template-driven
Webflow	Template	Designer tool; HTML/CSS-aware
Ghost	Theme	Handlebars templates + CSS
Drupal	Theme	Twig templates + CSS
Static site generators	Template	Varies (Liquid, Nunjucks, EJS, Astro components, etc.)

Where themes come from

Built-in themes. Bundled with the platform; usually free
Theme marketplaces. Curated collections (Squarespace, Shopify Theme Store, ThemeForest, WordPress.org Theme Directory)
Premium themes. Paid themes offering more polish or specialized features (often $30–$200)
Custom themes. Built specifically for a site by a developer or designer
Open-source themes. Free, community-maintained themes (common in WordPress, Hugo, Jekyll, Astro ecosystems)

Theme customization

Most CMS platforms allow theme customization at multiple levels:

Theme settings. Built-in options (colors, fonts, layout choices)
Custom CSS. Adding stylesheet rules without modifying the theme files
Child themes. A theme that inherits from a parent theme; safe place to make changes that survive parent theme updates (common in WordPress)
Direct edits. Modifying theme files; can be lost during theme updates unless using a child theme or version control
Custom themes from scratch. For full control

Strengths of using a theme

Speed. A site can be visually complete and consistent within hours
Cost efficiency. Premium themes provide professional design at low cost compared to custom development
Best practices included. Well-built themes follow accessibility, SEO, and performance standards
Updates and support. Maintained themes receive security and feature updates

Limitations of using a theme

Customization ceiling. Significant changes can be difficult without development work
Generic appearance. Popular themes may produce visually similar sites
Performance variability. Themes vary widely in code quality, page weight, and JavaScript usage
Update risk. Modified themes can break when updated unless changes are isolated (child themes, custom CSS)
Lock-in to the theme’s structure. Switching themes can be a substantial rebuild, especially for content using theme-specific shortcodes or blocks

Templates within themes

A single theme typically includes templates for:

Homepage
Standard pages
Blog post listings (archive)
Individual blog posts
Search results
Author archives
Category and tag archives
404 (page not found)
Custom post types or content types (products, events, projects)

Templates within a theme share visual styling and components but differ in layout and content arrangement.

Themes vs page builders

A theme defines layouts at the template level; a page builder defines layouts at the individual page level. Many sites use a theme that provides global structure (header, footer, navigation) and a page builder for designing individual page content.

Common misconceptions

“Switching themes is just a visual change.” Themes can include functionality (custom post types, shortcodes, widgets), and switching can affect what content displays correctly.
“Premium themes are always better than free ones.” Quality varies in both categories; some free themes (like WordPress’s default themes) are well-maintained, while some premium themes have significant performance issues.
“All themes are responsive and accessible.” Most modern themes are, but quality varies; testing is recommended before committing.