What isthe purpose of "HEAD / HTTP/1.1" or "GET / HTTP/1.1"?

I see these entries often in my web logs

[Wizcrafts]

These items keep showing up in my web logs and I would like to know what they represent, in tech terms.
1: "GET / HTTP/1.0"
2: "GET / HTTP/1.1"
3: "HEAD / HTTP/1.1"
Sometimes these requests preceed requests for other pages, and sometimes they are all alone.

Wiz

[WarmGlow]

"GET / HTTP/1.1"

The three variables enclosed in quotes are Request Type, Document URI, and Protocol.

Request Type: GET, HEAD, POST, PUT, DELETE, CONNECT, OPTIONS, PATCH, PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK, UNLOCK, TRACE.

Document URI: Forward slash only (/) is a request for the domain root index file.

Protocol: HTTP/1.0 or HTTP/1.1.

A HEAD request asks the server to reply with the document headers. Here is an example server reply to a HEAD request:

HTTP/1.1 200 OK 
Date: Fri, 29 Aug 2003 17:59:13 GMT 
Server: Apache/1.3.27 
Cache-Control: max-age=86400, must-revalidate 
Last-Modified: Tue, 26 Aug 2003 22:19:18 GMT 
ETag: "c20bf0-216b-3f4bdce6" 
Accept-Ranges: bytes 
Content-Length: 8555 
Connection: close 
Content-Type: text/html

[Wizcrafts]

The three variables enclosed in quotes are Request Type, Document URI, and Protocol.

I knew that, I was am curious what purpose would be behind requests coming in for only these headers and not any of my web pages? Is this the mark of a S.E.? Most human visitors leave a trail of web pages, ads, images, etc. These log entries usually want nothing more that a HTTP response. It has me curious.

[Xiaoth]

The "/" is the resource indicator, or in this case root index of your site.

So if you have, say, "index.html" in the root directory of your web site, the request "GET / HTTP/1.1" is a request for that file. Make sense?

[Wizcrafts]

The "/" is the resource indicator, or in this case root index of your site.
So if you have, say, "index.html" in the root directory of your web site, the request "GET / HTTP/1.1" is a request for that file. Make sense?

Thanks for the explanation Xiaoth. Now I understand why no filename follows those requests. This will help me when I analyze statistics and takes away the worry about nefarious activities.

[WarmGlow]

Wizcrafts wrote:

Thanks for the explanation Xiaoth. Now I understand why no filename follows those requests.

Apparently you did not read the following line in message #2:

Document URI: Forward slash only (/) is a request for the domain root index file.

[Wizcrafts]

You're right Warmglow, I missed it. Thanks for the explanation.