Drupal powers literally millions of websites. Among countless others, it is the system used to power the websites of Amnesty International and the White House.
If you look at those websites you will see that Drupal is completely customizable. It’s customized with templates that define the appearance of the pages, and modules that add different functionality (like that rotating banner image on the front page). No two Drupal websites need look or feel like one another.
Your website has been customized for you. Its appearance and functionality were decided in the process of creating a theme (a set of templates) choosing modules (a set of functionality) and configuring the various available options.
As you use the website, you are responsible for creating and updating the content. Drupal will take care of how that is laid out in a page and it will make a lot of decisions about what is presented and where. If you create an article it will display it at the top of the list of articles as the most recent one and if you create an event, Drupal will automatically stop displaying it once the event has happened.
To meet the needs of the various visitors to your website, you will need to post various different types of content and make sure they are kept up to date.
The content needs to be displayed in the right place and removed when it is no longer relevant.
The task of managing this content is made much easier by a ‘content management system’. A well-known example of a system that manages content is Facebook. You type in a message, add a link or upload a photo and Facebook takes care of the rest. It chooses where and how (and to whom) those items are displayed. The system that manages the website (called ‘Drupal’) is a bit like this – you add the content and Drupal will take care of how and where it appears on the website. If you can add and delete posts and images from a Facebook page, you will be able to use your new website.