An interviewer will ask this type of question to determine if you stay abreast of new developments in the web development industry. Technology changes very quickly and to be an effective web developer you need to stay current on evolving developments in this field. You should also be prepared to describe how you do this, such as reading blogs, attending training, watching videos and working with your peers to improve your skills and knowledge.
"Since I've been working with HTML5 for several years now, I am very familiar with the input types which have been added to this programming language. Some of these include color, date, datetime, e-mail, month, and number."
"As a web developer, it is important for me to stay abreast of evolving technology. I do this by a number of different means, including reading blogs and articles about the technology, attending industry conferences, taking advantage of inhouse training opportunities, and working with my peers to share new things that we've learned. Some of the input types that were added to HTML5 recently include color, date, search, number range, and URL."