HTML (HyperText Markup Language) and CSS (Cascading Style Sheets) are both languages that are used for web development. HTML is used to structure the content of a website, while CSS is used to control the styling and layout of that content.
A HTML developer is responsible for creating the structure of a website using HTML tags and elements. They may also use CSS to style the website, but their main focus is on the HTML structure.
On the other hand, a CSS developer primarily focuses on styling and layout, using CSS to control the visual appearance of a website. They may also have some knowledge of HTML, but their main expertise is in CSS.
When you are building a site, you will typically need BOTH types of developers in order to be successful.