Whether you're on a phone, tablet, or giant monitor, you're going to see this site render the same way. You have responsive design to thank for that. It's an essential skill for web developers to know these days, so if your career goals focus on web design, you'll want to know all about making sites responsive with HTML and CSS.
Defining Responsive Design
Think about your day on the internet. You might have looked at your favorite news source on your phone this morning before going to work, and read that same news source on a desktop computer during your break. You entered the same URL in the browser on your phone and your work computer, and the site rendered as perfectly on the small screen in your hand as it did on the large screen on your desk. That's what responsive design is all about.
We use the internet on a variety of different devices these days, which means that websites need to be able to look good on screens of all sizes, and load without breaking. There's no longer a clean separation between mobile sites and desktop sites. The days of putting up a special ""m."" URL for mobile users are mostly in the past. Instead, web developers build responsive sites that automatically scale to the size of the user's device.
The Limits of Responsive Design
Responsive design is the purview of web developers. Though it's focused on making the web usable for everyone regardless of device type and size, it isn't a mobile-specific concept. So it's not something you're likely to learn a lot about in an app developer course that helps you become an iOS developer. The web browser on your phone is just one app of many. It's a mini-version of the big browser app that fills the screen on your laptop or desktop computer. So when we talk about responsive design, we're talking about web design, not app design.
Responsive Web Design Tools
The tools used to build responsive websites are the same ones you'd use to build any site (HTML and CSS). There is responsive HTML code and mobile responsive CSS that's specifically useful for allowing a site to resize itself properly based on the size of the screen it's loaded on. These are generally the latest versions of HTML and CSS (mobile has become a major concern in the relatively recent past, so the earliest versions of these coding languages aren't built for mobile responsiveness). It's all just a matter of knowing the right tags and selectors to use with specific elements of the site to make it respond to screen size.
How to Learn Responsive Design
If you already know the basics of web development but learned to code long before the advent of responsive design, you simply need to take some classes in responsive HTML5 and CSS3 to brush up your skills. Once you learn how to make responsive web design with HTML5 and CSS3, you can easily stay up to date on the latest updates to those standard web languages to continue incorporating the responsive design approach into your code.