Check out example codes for "html with lang". It will help you in understanding the concepts better.

Code Example 1

<!DOCTYPE html>

<html lang="en"> <!-- sets language to english -->
  
<!-- <head>, <body>, etc. contents-->

</html>

Code Example 2

<html lang="en">
  <body>
    <h1>Detects you are using english</h1>
  </body>
</html>

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