What is the difference and what affects the performance of using .hpp or .h files in c++?

I am studying the templates in c++ but in the book they use .hpp files and in the videos I have seen the templates are placed in .h files in some videos I have watched however in the book it uses .hpp it does not explain why and the benefits, I would like to understand why ?

What is the difference and what affects the performance of using .hpp or .h files in c++? Could you please help me. Thanks

There's no difference, they're just different names. Includes are handled by the preprocessor, and it doesn't care what names your files have, you can end your headers in .blub or .ramons_special_header and it'd make no difference to the compiler (technically speaking the same is true of other source files as well, you could put C++ source code in a .c file, but there compilers that support multiple different language modes like gcc may change how they behave by default depending on what you name your files, but most compilers will have settings to override that behaviour anyhow).

The only reason people use different names is because some names are used for special purposes in certain projects (e.g. .hpp meaning "C++ header" and .h meaning "C header" in some projects with mixed C and C++ sources), or because some people have their editors configured to treat certain files differently based on name. Beyond that it's just a matter of preference. Some people use file endings like .hh or .hxx or .H, and if you search for it you'll find heated discussions about which name is best.