Hey Aamir,
Basically, this is an account that you could get from Google (for testing purposes) which has some restrictions (like 10 searches per day or something like that). Once the tests are successful, I believe you would request a formal/permanent/paid type of account from Google.
You can get (create) a Custom Search Engine from Google - by accessing: https://cse.google.com/cse/create/new
- create a custom search engine
- in the Basics tab -> Details -> Search engine ID button reveals the Search Engine ID value
Note: its of format: 1234213123231232:abcdef1234
Next step is to get a google API key. To get a search API key go to: https://developers.google.com/custom-search/json-api/v1/overview
- get a key, normally you get prompted for a project name followed by enabling a key that you copy/paste.
(see what projects/APIs you have: https://console.developers.google.com/apis/dashboard )
Note: APIKey is of format: abcd1234xyz1234def
Hope this helps
_R