WordPress and Drupal both are CMS (Content management Systems). But each have there own pro's and con's. So let's discuss here how they differ from each other and which one is best option for you.
WordPress is probably the easiest CMS for beginners. Wordpress started as just a bloging application but it soon took a path of popularity and now its common choice among developers and clients to make simple but effective Content management application It has ten times more users than Drupal, but that’s only due to its ease of use and popularity. Initially instituted as a system for blogs, WordPress evolved into the fully-functional CMS that is now, positioned as the biggest tool for website creation in the world. It has its own web hosting and at the moment it’s being used by about 1/3 of websites on the entire Internet. Using WordPress is great for a beginning blogger or website builder, but advanced users and developers can also have fun with lots of interesting features.
As wordpress evolved developers around world develop plugins around wordpress by using them you can create marvelous application ranging from just content management to simple e-commerce application. Most of plugins in wordpress are free and you can use, customize and do whatever you want to. Also, with theme, you can get lots of free theme over WordPress
When it comes to plugins and themes, Wordpress has the game down-pat. Drupal I don't think will ever come close to the number of plugins and themes Wordpress has and for some, that might be a deal breaker in making a decision and for those who don't need plugins/themes and are happy to coding their own functionality, Drupal is probably a good choice.
But wordpress has its own restrictions, If you wish to make product based site with user role management and access rights, wordpress is not best platform
Drupal is a free open source CMS that allows everyone to build websites and other complex web projects. With the CMS, you can create blogs, personal or business sites, forums, online stores, intranets and even social networking sites. Although it can be used both by beginners and professional, Drupal is more suitable for experienced users who know a thing or two about web technologies and coding. As you can imagine, building a social networking site from scratch can’t be categorized as easy. If you are wishing to making an application which you think as product where you have lots of users, their associated roles and permission. You have right choice with you "Drupal". With Drupal your development is fast, as Drupal itself manages Users roles and permissions associated with it.Multi-national or multi-lingual sites can be easily deployed with out of the box drupal features. If you are publishing module on your own, there are few ready made modules which are very helpful to speedup your development:
1) CCK - Content type creation module. With this module you can create content type in Drupal. Content type is core essential area in drupal development. when you create content type in drupal, it makes table in database. With this you can save your time of creation of tables in backend. You just need to have your table structure ready with you and follow up the content type creation method you'll get table ready in no time. These content types you can use in your development. When you insert records in these content types, it count as one node.
2) Profile2 or Content type profile: - When you define content type if you select it as user profile, you can use this content type as user registration.
3) Login destination: - After login, if you wish to redirect user to particular page then you can use this module to redirect user to that page with out doing any coding
4) PHP: - Allowing PHP code to be executed in blocks and pages.
5) Rules: - With this module you can right certain rules like, if user is doing registration and you want to store user's photo height and width in aspect ratio, then you can use rules, like if content type is going to be save and type is registration, then do this. And this all is GUI based. so you can make this task in few mins.
6) Views: - This is incredible module in drupal, its GUI based view writing module. You just need to select content type, if fields, if you want to apply some filters on it and then publish it, you'll get your results.
Security
Security is one of the biggest difference between Drupal and WordPress. While Drupal, and the entire open source community, has seen its share of security fears the platform has enterprise level security and provides in-depth security reports. It’s due to that level of security that you’ll find even governments websites build using Drupal globally.
It is important to note that with the release of Drupal 8 last fall, Drupal 6 has transitioned to unsupported status. If a new, unforeseen security issue makes Drupal 6 vulnerable, you unfortunately won’t receive any direct support. The volunteers in the Drupal community have shifted their full attention to Drupal 8 development and Drupal 7 support, so there is a lack of resources necessary to release security fixes. The best way to avoid any security vulnerabilities is to upgrade your site from Drupal 6 to Drupal 8 as soon as possible.
WordPress has traditionally been vulnerable to hackers and other attacks. Many of the plugins that make WordPress so powerful can also open up the system to potential problems. There are hosting platforms that make WordPress less vulnerable. One of the most popular is WP Engine.
On Drupal’s side, hosting with a partner such as Acquia or Pantheon will also help mitigate your risk of server vulnerabilities.
Conclusion
Overall, Drupal is powerful and flexible. In the right hands, you can create unique and effective solutions to meet your needs. If you’re looking for a website to support a blog or a small business, WordPress’s simple and easy-to-use interface will serve you better. Drupal is ideal for complex, highly customized sites that require scalability and large amounts of content to be organized. Both Drupal and WordPress have active user communities that are available to provide documentation and answer questions. The release of Drupal 8 also continues to make the platform easier to use for non-developers, including site builders and content authors. Wordpress is like an amazing hammer that can pound out simple sites quickly. Drupal is like having a garage full of tools that can build simple or complex sites, but requires more knowledge, planning and patience to achieve the result you are looking for.
I hope this helps you decide which one to pick for your requirements. :)