Web design and web development are distinct yet closely related disciplines in the creation and maintenance of websites. Here are the key differences between the two:

**Web Design:**
1. **Focus:** Web design primarily focuses on the visual and user interface aspects of a website. It’s concerned with the aesthetics, layout, and overall look and feel of the site.

2. **Responsibilities:** Web designers are responsible for creating the website’s visual elements, including color schemes, typography, imagery, icons, and overall design concepts.

3. **Tools:** Designers use graphic design software like Adobe Photoshop, Illustrator, or design-oriented web development tools to create mockups and visual assets.

4. **Skills:** Skills required include graphic design, layout design, knowledge of design software, and a strong understanding of user experience (UX) principles.

5. **Output:** The output of web design is often a design prototype or mockup, which serves as a blueprint for the web developer to build the actual website.

**Web Development:**
1. **Focus:** Web development is primarily concerned with the technical aspects of building and maintaining a website. It deals with coding and programming to bring a design to life.

2. **Responsibilities:** Web developers write the HTML, CSS, JavaScript, and other programming code to implement the design and create the website’s functionality.

3. **Tools:** Developers use text editors or integrated development environments (IDEs) to write code. They also work with content management systems (CMS) and databases for dynamic websites.

4. **Skills:** Skills required include proficiency in programming languages (e.g., HTML, CSS, JavaScript), server-side scripting languages (e.g., PHP, Python), database management, and knowledge of web development frameworks.

5. **Output:** The output of web development is a fully functional website that users can interact with. It includes the coding, databases, server setup, and any back-end functionality.

In practice, web design and web development often overlap, and professionals in both fields collaborate closely to create a complete website. The design and functionality of a website should work harmoniously to provide an excellent user experience. Depending on the project’s scope and team structure, some individuals may specialize in one area, while others may have skills that encompass both design and development.