Well, there are many reasons why one should or would choose Drupal for their website. Out of the many, few reasons stand out:
It is free and is an open source
Drupal CMS is free a software built in PHP. Also, it is open source, which means that the source code of all the scripts is available for you to view, modify, hack, redistribute and do whatever you want.
Drupal comes with many in-built features
Drupal comes with so many in-built features that most of the regular websites can be developed just by installing Drupal and configuring it properly. For example, User login, profile creation, blogs, forums, news feeds, creation of pages, input filters, and many more. These are some of the common features that you would want to build a content management system or a social networking portal.
Thousands of contributed modules and hundreds of free themes
One of the most significant reasons for the huge success of Drupal is its online community of developers who passionately develop and share their modules with others. If you browse through the Downloads section of the Drupal.org website, you will find thousands of free modules with a wide range of features under different categories. For instance, you can develop the following websites seamlessly with Drupal:
- Community web portals
- Discussion sites
- Corporate web sites
- Intranet applications
- Personal web sites or blogs
- Aficionado sites
- E-commerce applications
- Resource directories
- Social Networking sites
This is really amazing.
The module development is beautifully integrated
If you do not find the right module that suits your need, building a new module is needed. The Drupal architecture is built in such a way that if you adhere to the standards and conventions, you can build modules that will easily integrate with the rest of the website and many other modules seamlessly. This is a great advantage because you can always do module development and feature enhancement in phases; one at a time without having to worry that one might not fit into another at a later date. There are so many free themes available that you can pick one and start your website immediately if you like a design.
It's secure, SEO friendly, and user-friendly
The core modules and the contributed modules have been tested by numerous developers and bugs have reported, fixed well before the official release takes place. The code is reasonably very secure and the wrapper functions around database queries make it a secure database layer.