String formatting pls explain it with an example why I will use it

Answer 1

Here articles with examples:
https://realpython.com/JUMP_LINK__&&__python__&&__JUMP_LINK-string-formatting/
https://www.pythonforbeginners.com/basics/strings-formatting

Tip:
Google "Python string formatting" to see more examples and variants.

Answer 2

State of art is string templates.
What for? It is always the same:

Write code that is short and maintainable and readable.