PyScript is a framework that allows users to create rich Python applications in the browser using HTML’s interface. PyScript aims to give users a first-class programming language that has consistent styling rules, is more expressive, and is easier to learn.
in short :

• PyScript is a framework used to build web application using python
• used inside an html tag
• similar to script tag for javascript
• Enable using Python libraries with HTMl

For more info about Pyscript: https://pyscript.net/.

For more examples: https://pyscript.net/examples/