When using the Google Places API, what is the difference between "using the JavaScript library" and "calling the API directly"? - google-maps

Question

I have seen the two forms of reference to the Google Places Library/Service, using JavaScript vs calling the API directly, a number of times, but I don't understand the difference. The Google Docs don't describe anything about two methods of accessing the API.
For example, this question talks about 2 ways of accessing the API: OVER_QUERY_LIMIT in a loop
And it appears that there is some type of direct web access taking place in this question: Querying Google Places API using jQuery
Is this something where there was an old way that involved formatting URL parameters and the new way is by utilizing the JavaScript library calls?
FINAL SUMMARY EDIT: There are two distinct ways of requesting data from Google, as described in #Dan Nissenbaum's answer below. And since my original question, the QUERY_LIMIT question referenced above has been edited to also include more information about the two options.

Answer 1

Perhaps you are referring to the distinction between the Google Places API that is intended for use on the SERVER (i.e., utilizing PHP to call the Google Places API directly), and using the completely different approach of the Google Places Javascript Library in which the BROWSER executes Javascript using the Javascript library provided by Google (that internally wraps calls to the Google Places API, so that you, as a Javascript programmer, only need to understand the Javascript library provided by Google, and use that)?
Here are the two scenarios.
Scenario #1: Use the API directly. For this method, you must refer to Google's API documentation for the Google Places API: https://developers.google.com/maps/documentation/places/.
Using this API works as follows (giving a simple example only). Say you want to retrieve places within 1000 meters of latitude=-27.2531166, longitude=138.8655664. You need to hit a URL as described by the API documentation: https://developers.google.com/maps/documentation/places/#PlaceSearchRequests.
In this example, the URL looks like this (it's long):
https://maps.googleapis.com/maps/api/place/search/json?location=-27.2531166,138.8655664&radius=1000&sensor=false&key=AddYourOwnKeyHere
You need a key for your personal use, which I assume you have. There are other options you can specify, such as limiting the results to restaurants, etc.
When you hit this URL, the data will be returned in either JSON, or XML format, as specified by the text json in the URL above (use the text xml for xml). This data is returned exactly like data is returned from any URL call when you hit a URL in your browser.
You can test this by simply typing the URL directly in your browser, and see the results.
To use the API directly from code, you will need to use code that hits the external URL above within code and retrieves the results within code (for example, using the PHP CURL library, or using AJAX in Javascript).
Scenario #2: You use the Javascript library that Google provides that wraps the API, so you don't need to deal with it. I'll update the answer with more details about this, if you don't know what this is.

Answer 2

The docs do discuss the two different approaches. The Places Library utilizes the Google Places services from within the JavaScript Google Maps API. If you are using the Google Maps API in a browser, this is probably the approach for you:
https://developers.google.com/maps/documentation/javascript/places
There is also a web service, which allows you to query directly from your application. You query it using direct http calls to Google services. If you need access to the data on your server or a mobile device, this is the approach you want to take:
https://developers.google.com/maps/documentation/places