Responsive Design is a framework which means a website will display on various devices in an accessible manner including Smart Phones, Tablets and Desktop computers. Google views this type of framework as a Ranking factor so you should ensure that your website is built on a Responsive Design Framework.
A slider is a graphical way of communicating key messages in an immersive and impactful manner. Sometimes considered to be the ‘Hero’ graphic in web design parlance, the banking industry has made this approach more popular, following their own research into UX design.
You want to ensure that any website you develop is optimised with built-in tools for your market sector. Built-in tools come in a variety of forms and add additional functionality – for WordPress they are usually called Plugins, while Joomla refers to them as Components.