WordPress is a free web software or Content Management System (CMS) that helps a user to create, manage, update and organize content such as text, video, images and audio on his/her website. WordPress is a powerful and versatile tool which is best used for business websites, blogs and small –medium sized websites.
According to a report titled ‘Usage of CMS for Websites’ published by W3 Techs, Web Technology Surveys on their website in January 2015, out of all the website that are using content management systems, 24.2% are using WordPress. As far as Google Trends is concerned, it sees WordPress as 5 times more popular than Joomla and nine times more popular than Drupal.

Forbes magazine published a story titled ‘With 60 Million Websites, WordPress Rules The Web. So Where's The Money?’ in its 2012 issue in which it was stated that every one out of 6 websites on internets run with WordPress. It means about 60 million websites in totality.
According to list of 100 most popular websites as of 26 March 2015, prepared by Alexa Internet, WordPress.com is the 33th most popular website in the world.

According to Torque, a news site dedicated to evolution of WordPress, worldwide monthly searches for WordPress is 37million.

Top websites such as TechCrunch, BBC America, Star War Blogs, MTV News, Quartz Blog, etc. are using this quality platform.

In the light of above mentioned researches and statistics we can say that WordPress is the most popular CMS in the world.
There are number of factors that have resulted in making WordPress the most popular and commonly used CMS in the world. Let’s have a look at those factors.

Among the three monsters of CMS; WordPress, Joomla and Drupal, WordPress is the easiest and simplest CMS. You can build websites with WordPress without the need to know any code and complex program. You can easily and quickly make changes in layout, content and functionality of your website built on WordPress. WordPress dashboard is extremely easy to use even a person with little information about site creation can use it.

We are no more dependent on web designer to alter things on our website as we can make changes or add content in our website by our own from anywhere in the world with laptop or computer having internet facility without the need of any special software. If you don’t want to manage your website all alone you can give access of the website to other users as well.

Search engines love WordPress websites. It is evident from the fact that they crawl WordPress websites more deeply and more often than websites built on other platforms.
WordPress has simple and easy code. This code helps search engines to easily understand and index website’s content. Whenever, we add new content or update website’s existing content Ping feature of WordPress automatically notifies search engines about it. Then search engine goes through our updated content to know what more we can offer.

If our website is built on WordPress we don’t need to create mobile version of it because they are compatible/configured for mobile phones .We can also use plugin like WPTouch to make our site mobile friendly.

WordPress is not only easy to install but also quick to install software. Automatic installation of WorPress websites through web hosting companies takes 5 minutes. Manual installation process takes less than 1 hour.

WordPress is free to use. It offers plenty of free stuff such as 20, 000 + themes and 27,000 + plugins to help you save your money.
WordPress offers plugins to help you improve functionality of your website and it provides themes to help you change overall look of your website.

Speed of WordPress website is not suffered by how much new pages or blog posts you add to your website. You can add thousands of new pages and blog post easily without hurting speed of website.

If you ever get any problem with your WordPress website then take it easy because WordPress Community is big and dynamic, and you can get help from WordPress forum or from web design agencies specialized in WordPress.