Client Process Tool
The Client Process tool shows the name of the local client process that is responsible for making each request. The client process will usually be your web browser, such as firefox.exe, but there are many potentially unknown HTTP clients that the Client Process tool can help you discover.
The client process name is displayed in the Notes area on each request.
The Client Process tool is useful if you can see requests in Charles that you're not sure of the origin process. It only works for requests originating on the computer on which Charles is running.
This tool will introduce a short delay before each connection is accepted by Charles. The delay is usually not noticeable or significant.
Selected Locations
The tool can be enabled for every request or only for selected locations. When used for selected locations you limit the tool's effects to specified hosts and or paths using simple but powerful pattern matches.