users can change the title, add hashtags, and even
retrieve the URL to which the video will be posted once it
is finished being uploaded.
In summary, the main difference between synchronous
and asynchronous APIs is that a synchronous API waits
for other aspects of the code to complete prior to moving
on and processing additional code. An asynchronous
API, on the other hand, provides the ability to continue
processing code and provides a callback so that an
application doesn’t have to wait for the API call to
complete before it can continue processing other API
calls. An asynchronous API provides a better user
experience as the users do not have to wait on certain
aspects of information to be received prior to being able
to use the application for other things. Figure 6-3
illustrates an asynchronous API call and how the
application can continue processing while waiting for the
response from the initial API call.
Figure 6-3 Asynchronous API Call Example
Representational State Transfer (REST) APIs
An API that uses REST is often referred to a RESTful
API. RESTful APIs use HTTP methods to gather and
manipulate data. Because there is a defined structure for
how HTTP works, HTTP offers a consistent way to
interact with APIs from multiple vendors. REST uses