A web design is that aspect of a website development which deals majorly with the design and layout of the site. A web designer is responsible for the overall look and feel of the website and working on the user experience for an end user. He is the one who decides on the theme of the website and chooses the design, typography, color scheme, layout and visuals (and optionally, audio) for the website.
Web development, although is a broader term encompassing all the aspects of a web site development typically focuses on the technical aspects of the development process. A web developer works towards the functionality of the website, without bothering much about the overall aesthetics (which is the job of a designer).
For instance, if the project is about creating a web site for online shopping, the web designer is the one who will first decide whether the website has to be given a formal feel or a casual, friendly feel. He then decides the color scheme, how the products will be displayed, and what audio/visual aids will be present on the web page to make the end user feel at home, to make the shopping experience more real. The logo, navigation features and even the tone of the messages to be displayed to the user come under the responsibility of a web designer. A web developer will work towards making it a fully functional web site. Like what should happen when a user clicks on the “submit” button? Or how the payment gateway is secured so that the credit card information of the user is not compromised? Or how the billing calculations happen once the user checks out the products in his/her cart? All this functionality is programmed by the developer.
As is evident from the job description, the skill set required for both the jobs is different. The designer needs to have a deep understanding of aesthetics and user experience, apart from graphic designing. So he is one who would have knowledge of HTML, flash, Silverlight, CSS etc. A developer needs to be a good programmer and should talk in the language of algorithms. Technologies like JAVA, ASP. Net etc. should be at his fingertips.
While the roles and responsibilities of a designer and developer are like chalk and cheese, they work for the same end product. It is as if the designers make use of the right half of the brain (the creative folks) and the developers use the left half (the functional folks). Are they really two different people (or teams)? May or may not be. A single team can handle both the jobs in some scenarios, but larger projects need dedicated teams for both the jobs.
Another major difference between the two is the difference in their paychecks. While the developers earn a hefty paycheck of thousands of dollars, and anyone talking in C++ can be hired as a developer (just joking), the designers are typically hired on a need to need basis, and earn just a fraction of the developer’s salary as wages.