Your First Kotlin Android App: An App From Scratch

What is Android?

Well, Android is a mobile operating system just like Apple’s iOS. But you’ve heard the phrase “Operating System” a lot times. You know about Windows and MacOs. But what really is an operating system?

An operating system is a software tool that gives applications access to the power of the hardware bundled in our mobile devices. So an operating system is kind of like an intermediary between the hardware and the software that would run on the device.

To make this explanation clearer, let’s use this analogy.

Imagine a building site with all the materials and machinery, let’s envision them as hardware.

Then you have the workers, let’s envision them as the software.

Then imagine there’s a building engineer who conducts and intergrates these two groups to work effectivley together.

The building engineer in this case would be the operating system.

Because, the workers wouldn’t be able to fully utilize the tools and machinery to produce the end goal if there’s no intermediary that gives them direction and access to the capabilities of the materials and machinery. The workers need the building engineer. The workers need an operating system.

The same way our apps need an operating system like android to run on.

And that’s also the same way an airplane needs an operating system so the pilot’s navigation app can communicate effectively with all the hardware in a plane.

You get the idea?

Now, take my android phone as an example. This phone has accelerometer hardware built into it. The accelerometer sensor measures the rate of change of motion. The android operating system in this case, communicates with this hardware and provides an interface to report changes in device orientation for example.

I’m currently running a browser android app.

Whenever I rotate my device, the app gets the accelerometer information from the operating system and rotates its layout.

Without an operating system, you’ll have to write tons of low level code to be able to use the hardware that comes with modern devices.

Now as technology advances with modern hardware like depth sensors on cameras or fingerprint scanners on phones, the Android operating system updates to newer versions that integrates these new hardware.

The Android operating system is not just limited to phones. It runs on tablets, TV, automobile and even smart watches.

Now that we understand what Android is, then what exactly is kotlin?

Well, Kotlin is simply the programming language you write your android apps in. It is a modern programming language that reduces the amount of code you write to build apps. It also reduces common code errors that usually occured when the Java programming language was used to develop android apps. It also works well with Java and has modern features for code that runs in the background.

You’ll be working with this expressive language recommended by Google throughout this course and in the learning path. So you’ll be learning how to work with it hands-on.

So Android is the operating system while kotlin is the programming language you use to build apps that run on android.

Okay!!! Let’s get started with this course, shall we?