A WordPress theme allows the user to make changes in the design or layout of your wordpress enabled website. Changing the activated theme changes how the site looks to the end-user or visitor when they visit your site.
Themes allow the content and data stored in the website to be presented differently by Wordpress to the end-user without affecting the underlying data. Essentially changing the theme changes the presentation but does not change the articles or information that the user has stored within the site.
Wordpress websites come with a default theme installed. Additional themes are available for free or as premium content from developers. There is an endless array of designs and options – one of the reasons Wordpress has become so popular.
“Themes affect the design of your entire site, and templates affect the layout of a single page on your site. Another area where themes and templates differ is in terms of quantities; You can only have one WordPress theme active on your site at a time, yet you can have multiple templates on your site.” per Elementor.