A style sheet language is like a set of instructions that tells a computer how to make things look pretty on a website.
Imagine you have a coloring book, and you want to color the pictures inside. The pictures are already there, but you want to choose what colors to use for each part. The style sheet language is like a magical set of rules that you can use to decide the colors for everything in the book.
Style sheet languages have different rules for different parts of the website. For example, one rule might say that all the headings should be big and bold, while another rule might say that all the paragraphs should be smaller and in a different color.
The cool thing about style sheet languages is that you can use them to change the look of a whole website at once! Instead of going through each page and manually changing the colors, you can just update the style sheet and all the pages will automatically look the way you want.
So, in a nutshell, a style sheet language is like a magical set of coloring rules that makes websites look pretty!