Narrator: So let's talk a little bit
about the importance of API.
So the question basically is, why do I need an API?
Is it really such an important part
of the software that I'm developing?
So the answer is a sound yes.
It's really, really very important.
And let's understand why.
So the APIs that you will develop for your backend software
will be used, first, by your user interface,
and you will understand it in a minute.
In addition, it can be used to extend your app's reach,
and also to allow monetization.
Let's understand this.
First, about the user interface.
Modern apps are built mainly for web and mobile.
You probably know that, you probably use web apps
as well as definitely mobile apps.
Now, the thing to know about mobile apps
is that in order for them to access your backend server,
your backend server must have an API
in order to communicate with it.
There is no other way for the mobile application
to access your operations data.
You should remember that the mobile app
is a separate application,
runs on the separate machine, on a separate process.
It has no other way to access the data and the actions
that are stored and executed on the server.
So if this is your plan
and you are developing a mobile app,
then you must use an API.
In addition, web clients that are built
using the single page application method
also must have an API on the server.
If you are not familiar with a single page application
or SPA method,
then suffice to know that SPA means that the frontend,
the part that the end user sees on his screen,
is built using sophisticated fronted framework,
such as React, or Angular or Vue,
and they run completely independent from the server.
So for those applications to access the web server
they are using API.
So the HTML is not render on the server
like some old fashioned framework,
such as the web forms or JSP,
but is rendered directly on the client.
And if the client needs some data from the server
it must access some kind of API.
Another important aspect of exposing an API
is that it'll allow your application to extend its reach.
For example, take a look at this screenshot from My Outlook.
Do you see the weather widget on the top of the screen?
In this case, it shows the weather in Washington D.C..
So if you look closely at this rectangle with the data,
you will see that the source of the data
is from a website called foreca.com.
So this is not a Microsoft website,
this is not part of Outlook.
But what happens here is that Outlook
accesses the API exposed by foreca.com
and displays the data it gets back from it.
So just think what would happen to your application
if Outlook will access it
and uses the data that it'll get back from it.
It'll help boost your application popularity,
and it'll definitely help your business.
And speaking about business,
API can be used also for monetization proposals.
You can charge users for accessing your data,
and there are a lot of examples for it.
For example, take a look at this page
from the Twitter developer's website.
So as you can see, if you want to access Twitter's API,
and Twitter's API is one of the most popular APIs out there,
then there are three levels of API access
you can choose from.
The first one is Standard, which is free
and allows you certain level of API access.
But the others level, Premium and Enterprise,
are paid level.
And if you want to use them to access more features
or to allow more usage for the API then you must pay.
And this is definitely a potential income
you don't want to miss.