How do the autoplay and muted attributes in the video tag affect user experience and webpage performance?

Autoplaying multimedia, especially videos with sound, can be disruptive to users. It's considered bad practice because it can surprise and annoy users. Some browsers block videos that autoplay with sound, but allow autoplay if the video is muted. By using the "autoplay" and "muted" attributes together, developers can provide a smoother user experience by having videos play automatically but without sound. However, always consider user preferences and the context of the webpage when implementing these features. Performance-wise, autoplay can lead to additional bandwidth usage, which might be a concern for users on limited data plans.