is the page a visitor arrives at on your website
Header , footer , body , sidebar , navigation menu
Theme , template , plugin
Theme : is defined as a collection of files like the templates and stylesheets that work together to define the appearance and unified design of a WordPress powered website.
Template :to-use with pre-set themes and styles. All you need to do is add your content
PS: template for home page , about us , services ,contact us so all templates together in the same desing we can say on them (theme)
A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress.