User Experience (UX) refers to a person’s emotions and attitudes about using a particular product, system or service. It includes the practical, experiential, affective, meaningful and valuable aspects of human–computer interaction and product ownership. As part of web applications, user experience is trying to understand what users need, what are their limitations and how the application can be changed accordingly in order for the user to easily interact with it.
Responsive Web Design
Responsive web design is an approach to web design which makes web pages render well on a variety of devices and window or screen sizes. Since most of users nowadays are using more than one device (mobile and laptop), web application must render well on each of them.