What is a WordPress Theme? — a practical guide to What is a WordPress theme with clear examples you can reuse in real projects.
WordPress Theme Development Series (2/96). Prefer one article? Read the complete WordPress theme development tutorial.
Short description
Themes provide templates, styles, and theme supports. Plugins add features; themes should focus on design and display.
Theme vs plugin
Theme → design, templates, presentation
Plugin → features, integrations, business logic
Best practice: keep feature logic in plugins when possible