Stucked in the "Images Search Abstraction Layer"


I am stucked in the project “Images Search Abstraction Layer”.

I am using Google Custom Search API. I generated the search engine I can access with the URL:, returning a JSON object with the result of my query:
“kind”: “customsearch#search”,
“url”: {

What I would like to know is what the web of my project returns exactly ( that I placed in the Control Panel in “Sites to search”.

What are the link between, the Search Box and the URL of my project that I placed in “Sites to search” of the Control Panel of my Customized Search Engine?