There are three types of matching you can perform in an ECCU request:
Path matching is used to describe the URL path
Request property matching is used to identify the request by some attribute other than its URL. Commonly used properties of requests include: query string arguments, file extensions, method (POST or GET)
Response property matching is used to identify the request by some attribute in the response from the origin server. In this case, there is only one match type available: response-header.
The table on the next page summarizes the available matches, and it is followed by an extensive discussion of the matches and how they are used.