Why WordPress is better than others CMS ?
Because it’s AWESOME and it is totally FREE and open source software licensed under GPL, with lots of layouts to choose from. 
WordPress doesn’t cost any single penny to download or install(WordPress comes with a famous five minute install). Most WordPress hosting providers also offer one click install of WordPress. This makes it fairly easy for a new user to get started with their website, and most important – there’s a huge community who has designed beautiful themes,templates and plugins making it easy to get going simple and fast.
It’s extremely beginner-friendly. WordPress is easy to use like MS Word. Any one who doesn’t know anything about web coding like HTML, PHP etc can use WordPress easily. WordPress features can be expanded with free plugins to handle just about any site you can imagine – from gorgeous business pages to social networking sites. With “plugins” you’ll be able to add contact forms, subscription forms, image galleries and so on for your website. The user sees a simple clean cut user interface with the menus to create posts, pages, or start customizing appearance and themes.
From basic blogs to beautiful business sites and eCommerce, WordPress can handle just about any kind of website. WordPress is used by famous brands like Facebook, eBay, McAfee, Mozilla, Reuters, CNN, Google Ventures and even NASA.
It’s mobile & tablet friendly. The website you build will be responsive, looking great on every mobile device, smartphone and tablet.
Why WordPress? Because it is supported by huge community. With so many people on the platform, it’s easy to find help when you need it, and lots of free resources you can dig into.
In fact, the site you’re reading right now is built with WordPress! It’s popular for a reason. Specifically, 25% of all websites are built with WordPress. If you’re interested in the details, here are more facts about WordPress.