Python and HTML?

Hello,

i have been using python for around a year, and have never understood how to use it in a .html file, or (if impossible) some how use Python in the web, because i have no clue you may need to explain as if i don't really know python.......sorry!
So, obviously i have checked google and youtube for the answer, but the answers confuse me!

Thanks a lot!

I have tried Django, but am needing help, because the combination with HTML in Django is something i do not know how to do? If there is a better way, (CGI) could you explain the Installation for either (or anything else that does the trick!)
Thanks!