Like all technology the internet is always evolving, and these are the popular trends for 2019.
Animated backgrounds and headers
Parallax - A special scrolling effect whichkeeps users on your page longer
Typography - Using different Typefaces in various sizes to create images
Icons - Vector (outlined) graphics
Serifs on screen
Minimalistic asymmetrical layouts
Picular and Pictaculous - Google and Google image search but for colors.