Question: The third section of a request message in HTTP is the__________

Answer:

The third section of a request message in HTTP is the "HTTP version".

The request message in HTTP consists of three main sections:

1. Request Line: This is the first section of the request message and contains the HTTP method, the target URL or resource path, and the HTTP version. For example, a request line could be "GET /example.html HTTP/1.1", where "GET" is the HTTP method, "/example.html" is the resource path, and "HTTP/1.1" is the HTTP version.

2. Headers: The second section of the request message is the headers. Headers provide additional information about the request, such as the user agent, content type, cookies, and more. Headers are key-value pairs separated by a colon (:) and are included one per line.

3. HTTP Version: The third section of the request message is the HTTP version. It indicates the version of the HTTP protocol being used in the request. The HTTP version is typically specified as part of the request line, following the target URL or resource path. Examples of HTTP versions include "HTTP/1.1" or "HTTP/2".

Here's an example of a complete request message with all three sections:
```
GET /example.html HTTP/1.1
Host: www.example.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.9999.99 Safari/537.36
Accept-Language: en-US,en;q=0.9
```

In this example, "HTTP/1.1" is the HTTP version specified in the request line.

It's important to note that the request message in HTTP can have additional sections, such as the request body for methods like POST or PUT, but the three sections mentioned above are the primary sections in a basic request message.