Class1 keypoint: Weekly blog update. Importance of RWD: Over 80% of users visit websites on smartphones or other devices other than a PC. Website rendering will adapt to the user's device's screen size and proportion. Front-end developers: Aesthetic and design of what users see on a webpage. Selecting and optimizing graphics, texts, or functionalities. Back-end developers: Works closely with databases needed for the website to work with the desired functions(such as user logins). Optimize servers for scalability, speed, and stability. Implements security. One page websites: Contain only one HTML page. Allows users to scroll down to access all contents. No need to click on tabs. Let smartphones users have a smoother experience when scrolling down a webpage.