What is API in Backend engineering...

API, application programming interface, a term that's way too long for what it does, which is connects apps together. This is the only video you'll ever need about APIs. After this, you're gonna understand everything. I'll also give you some examples of how you can build cool apps using APIs. So let's get started. APIs just connect apps together. And you can think of an app as just some code running on a server. Now you can connect a bunch of small apps into one large app, like a puzzle. And the parts where they connect are APIs. For example, when you book an Uber, you are the company I used to work for as a programmer. It might seem like one app to you, but there's hundreds of different apps running that you book that trip. One app is for your payment, one calculates your location, and one handles the review you leave at the end of the trip. And for each of these apps, there's probably a team of full-time software engineers in charge of it. Let's just take a look at the reviews app. To work, this app needs some data: who took the ride, who the driver was, and how many stars you left. This data is what plugs into the API. If the puzzle piece fits, aka the required data is received, then this app can do its job. We can also call the shape of this puzzle piece, the API definition. Now, it works in exactly the same way you fill out a form on a website. There's required fields for username and password. And if you don't have both, then the form is not going to submit because the piece doesn't fit. These kinds of forms are part of the UI or user interface. And notice the word interface is the same. UIs work for the user and APIs work for code. For example, in the login form example, you have the UI which connects to your front end code. But to check your password, it also has to connect to your back end through an API. In this case, the API has the same shape as the UI, expecting the username and the password. So this data will pass through the UI and then the API. Over here, we have the backend. We connect to the login part of our API. But APIs usually have multiple pieces you can connect with custom glue code. The trigger, for example, you can connect a new post in a Facebook group to publish that to your Slack channel. So that sounds pretty amazing, but how exactly do you know how to use an API or what shape the piece is? Well, where API docs or documentation comes into play. You can have to read up and understand APIs. So there is overhead involved in starting to use each API. Connecting multiple together, getting API keys, reading the docs, well, that's a lot and it kind of is. It does take time to set this up. But there's amazing tools like Zapier that allow you to connect APIs together with absolutely no code. And even if you can't write code, you can use a tool like Zapier to just do some amazing automation. So I recommend checking it out. And it's absolutely free to get started and start playing around with a tool like that. And not sponsored by the way. Anyway, that should give you a really good understanding of APIs. Just think of them as an interface for code instead of an interface for you. So if you have any interesting app ideas for connecting together, comment that below. With that said, hope you learn something soon.