HTTP supports a number of different methods, including:

• GET
• HEAD
• POST
• PUT
• DELETE
• CONNECT
• OPTIONS
• TRACE
• PATCH

These methods are defined in the HTTP 1.1 specification:

https://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html

It is common to find that a web server only supports a subset of these. In many cases, supporting too many methods is deemed to be a security risk. The Invoke-WebRequest command can be used to verify the list of HTTP methods supported by a site, for example:

PS> Invoke-WebRequest www.indented.co.uk -Method OPTIONS | 
    Select-Object -ExpandProperty Headers 
 
Key            Value  
---            -----  
Allow          OPTIONS, TRACE, GET, HEAD, POST  
Public         OPTIONS, TRACE, GET, HEAD, POST  
Content-Length 0