How is a website built? Who is involved and what are their roles? Generally speaking, these three roles enter into any custom site.
The web designer creates what the user sees. Their focus is on the aesthetics of the site. They keep up on trend in design and work within the branding guidelines to make the site look consistent, interesting and attractive. Web designers typically have a working knowledge of code, including html and css, though they most likely lay out their designs in programs like Photoshop, Illustrator or Fireworks.
The back-end developer makes the site “go”. They write the code that makes the whole site function, including user accounts, databases, news feeds, etc. According to a discussion thread on Reddit, “They’re the guys that pull off raw meteorological data from databases, and process it into lists of weather reports for a given day. They’re the people who write the “recommended items” lists for Amazon.” They tend to be focused chiefly on the functionality and less on the aesthetics.
It takes all three talents to make custom sites work. Some professionals are able to be a blend of two or even all three of these, but most likely people excel in one area and work best when paired with others.