A lot of people do not know the difference between web designing and web development. However, they are two different trades of the same field. It is not possible for a single person to be efficient at web designing and its development at the same time. Though, there are a few people who learn both the trades and handle everything related to website.
Web development involves creating the functionality and testing the usability of a website. However, content creation comes under web designing. A web designer has to be an expert at graphic designing tools like Photoshop. They should also know about HTML so that it becomes easy for them to implement their designs. It is also the responsibility of a designer to use graphics, animation and layouts on the website.
Owner of the site always gives his own content but a web designer is required to edit and rewrite it if necessary. Testing the usability for navigation and reloading speed of a site is also checked by the web designer. On the other hand, the functionality for the website is created by the web development programmers. They are also required to have some knowledge of HTML to carry out the usability testing for the functionality they have created.