Responsive or Adaptive Web Design

The W3C, or World Wide Web Consortium, coined the term "one web approach". The term relates to the idea of responsive and adaptive design techniques that are used to ensure that the same information and services are available to users, as far as it is reasonable, regardless of the device they are using.

From a developer standpoint that means not only ensuring that a site works on the smartphones and tablets that currently exist, but also are going to work on whatever tomorrow brings.

As a business what this means is that you need to make sure that your website is not only designed with either responsive or adaptive design techniques, but also that the company hired for this development is looking ahead to tomorrow along with handling your problems of today.

Responsive

This is the most common of approaches that modifies the presentation of a web page based on the size of the device display. There are a few advantages from the design side of things that can make it easier overall for developers.

For this type of design you need to often need to do a complete site rebuild. It works well for people who design a site for mobile users first and then scale-up to desktops. It can create challenges for site that have a lot of elements and images however this is lessened if there is more simple functionality.

Adaptive

Adaptive is different from a development sense in that they rely on predefined screen sizes. It is generally a more streamlined, layered approach that uses scripting to help with adapting to devices and screen sizes.

In this case it is the server hosting the website that detects the device making the request so it delivers different code based on the device. Ideally this type of site can capture user intent more precisely on a mobile device. Also a developer does not have to re-code the entire existing website from scratch.