Drupal is surely unknown to the elders. When asking “What is Drupal?” nothing would come to their mind. As grandpa and grandma are not into the tech world, it would be hard for them to understand what Drupal is right away. Let's take this short scenario as an example: Grandpa is a philosopher. He is pretty fed up with all the procedures and investment needed before getting his work published. Instead, grandpa now wants to create a personal blog online. Yet, he thinks that it is out of his reach and gets discouraged. That is when Drupal pops in to tackle grandpa's query.
With Drupal, he can create a website online without much technical knowledge. Basically, Drupal is just like a simple Microsoft word office. The main difference, it gets your content further by publishing your 'document' on the net. Likewise, Drupal allows grandpa to edit, manage and publish his writings. All this, only by accessing the internet. Thus, grandpa can also add pictures, increase text sizes and play with colours. On top of that, Drupal is an extensible and scalable tool. It can be thought as a pile of Lego blocks, with which you can build what you want. But sometimes, there are specific Lego pieces that you need instead of mere blocks. Drupal calls them 'modules'. For example, a module can help give your website a search bar. Hence, Drupal is here to meet Grandpa's need.
What more? Drupal is also 'open source'. Roughly, open source allows anyone to view, edit and share their modified source code. For example, let grandma's baking recipe be the open source code. It will be made public such that anyone can view, update and share the new recipe. (McDonald's is definitely not open source!) Furthermore, being free, grandpa does not have to spend anything to use Drupal. It is now the end of Drupal's overview. Surely, you now have an idea of how Drupal works.