There are 4 main theme components.
Templates: a set of templates for your website, including a homepage, about page, landing page, and blog templates.
Modules: a set of unique theme modules you can add and customize on any page template in that theme.
Theme settings: default settings for your theme's templates, including fonts, spacing, and colors.
Global content: theme templates include global content , like your website footer, which is repeated on multiple pages.