Understanding APIs - Application Programming Interfaces

-: Hello my friends. So welcome back and we're gonna talk here about APIs. Look, in your work as a product manager and in many other roles in the technology industry, you're gonna hear this term API a lot. Usually you're gonna hear some engineers talking about it and sometimes they'll be like, "Oh, well, we can't do that because the API doesn't allow us." So let's demystify that. What is an API? API stands for Application Programming Interface. The easiest way to explain it is that it's the messenger that takes requests and tells the system what you want to do. Then it returns what you requested, the information, back to you. Well, let's make it even more simple. Imagine you're at a restaurant and you're looking at the menu, and the kitchen has some delicious food, probably some barbecue, if it were me, and I'm like, I want that barbecue, but I need a way to get that food from the kitchen because they've gotta make it for me, and then they've gotta send me the food, so I gotta request it. They gotta make it. They gotta send it. And what I need in this case, like the missing link here, is a waiter. The waiter comes to me and says, "Hello, how many pounds of barbecue would you like, Cole?" And I'm like, "10 or 15 pounds." And then he goes back to the kitchen and he gets me 15 pounds of barbecue, brings it back to my fat self. So he's done all of this translating to kitchen language and bringing me the food. And that waiter is like an API. (bell dings) Also, in this case, the kitchen was a database, a database full of delicious barbecue, in our example. Okay, so there's two types of APIs. I know, it seems like it's getting more complex, but I promise it's not that hard. There's a public API and a private API. Public APIs are provided by companies to allow products or services to get data from their system. A great example of this would be on a travel search website like kayak.com where you can search for a flight across different airlines for the cheapest price. Kayak takes what you type in about what dates you wanna travel, and then using the public API of every single airline, or at least most of 'em, it returns to you the prices and availability for all of the trips. That's because Kayak does not have the information on all airlines at all times and all flights but they contact the airlines' databases through the API. They did this because the APIs for the airlines are public, which means that they let anyone, like a developer like Kayak and the engineers there just dial in and get that data and provide some services based on it. Why? Because now they're making more money. Because if Kayak does a good job of marketing, people are gonna come there and they're gonna search for flights and they're gonna buy more stuff from the airlines. So a lot of tech companies out there have public APIs to encourage developers to build products using their information. Here, you can see a documentation page for Twitter's public API. All right, so what's a private API? Well, these are APIs that are available only to the developers inside of a company to get information from different internal systems. It's example time again. At Facebook, there's probably a database that holds the pictures, and another database that holds the messages, and there's probably a lot of databases for a lot of different things at Facebook. So if a developer on one team, let's say this developer doesn't work on the photos team or the pictures team, but they want to code a new feature and they need access to the pictures database somewhere inside of Facebook servers, then they will write what is called an API call in their code, and they will write this API call to what is called an API endpoint. The database then sends back the pictures that they requested. By the way, this API endpoint is just a fancy way of saying access window or something like that. It's an address that allows developers to get a certain type of data. And sometimes the endpoints have limitations to prevent problems. Like maybe they'll say, okay, you can only send 100 requests per minute because if you go above that, it's gonna overload our systems, and things will crash and things blow up. (computer exploding) Anyways, yeah, don't worry about that. I just wanted to let you know that that exists. All right, I told you that was not very hard, but we're gonna recap anyways. Basically, APIs are just ways that developers can write code to other systems and get data from them. There are two major types of APIs, public APIs and private APIs. Public ones are available to anybody, including you, if you're a programmer. And then private APIs are available only to people inside of that company, which means not you, unless you work at that company. All right, everyone. I hope you're learning some stuff here. I'm gonna see you in the next lecture.