Need a quick tip for the HTTP PUT method

HI my name is Tobias and i have a question, around HTTP and HTML.

The http request method; PUT. does it only modify data that could be stored in the HTTP Response message "Entity Headers"(HTML) or does it work as a DELETE and a POST method in one, and can thereby modify all data in a URL? i know it's properly a stupid question since the HTML Entity Headers has "nothing" to do with the HTTP methods, or does it? i'm really confused from what wikipedia says.

Need a responce fast please, I have to upload my repport on Server technology soon ;(

Thanks in advance

and also, can someone please help me to understand http responce headers better, i'm not sure about "Accept-ranges" and "connection:" and really just the general understandment of everything combined. i've just started my studdies on html and http so i'm really lost. who would have known that riding a repport on http and html the same day you are first presented to it, would be confusing...