How would redirect one page to another page or even website using .HTAcess?

If some page on the website is not existing, and you need to redirect it to another page or even the website then a user can use the .htaccess file for redirection without wasting a minute.

Redirect from a page/directory to another domain or the main domain:

Redirect from one page to another domain:
RewriteEngine on
Redirect 301 /mypage.html http://example.com


Redirect from one page to another page

Redirect from a page/directory to another page
Redirect 301 /oldpage.html /newpage.html


so, when you open the url example.com/oldpage.html, it would automatically redirect you to new page such as example.com/newpage.html.