Exploring the diverse landscape of API types

Have you ever found yourself at a bustling city intersection, traffic whizzing by in every direction? That’s what it feels like diving into the world of APIs without a guide. But don’t worry, we’ve got your back.

Just as traffic lights manage the chaos on roads, APIs control data flow between different software systems, tying everything together into an efficient API experience.

Intrigued? In this whirlwind tour, you’ll navigate through web APIs’ busy highways and library-based APIs’ well-ordered streets. With hardware APIs, you’ll peek under the hood and sift through database API treasures. Object remoting and service APIs won’t remain strangers either.

Around each corner waits a new revelation about how these invisible orchestrators shape our digital lives daily. Fasten your seatbelt; it’s going to be an informative ride!

Understanding APIs

Application Programming Interfaces (APIs) act like the waitstaff in a restaurant. You sit at your table with a menu of choices to order from, and the kitchen is where those dishes are prepared and cooked. But how does your order reach the kitchen and then return to your table? That’s where the waiter – or API – comes in.

The API takes your request, tells the system what you want, gets it for you, and delivers back what you asked for – all without you needing to know how any of that happens behind the scenes. Just like when dining out, you don’t need to understand everything about the culinary arts to receive your meal.

This process makes APIs invaluable tools because they let different software systems communicate effectively with each other. For instance, websites with a Google Map use Google Maps API.

APIs enable interoperability between diverse software systems and create more efficient code by reducing redundancy. They make updates more accessible, too, as you can change things in the background without impacting users directly. Let’s explore some of the APIs you can use to do this so you can consider which type of API might be best for your next project.

Web APIs

Web APIs, including HTTP APIs, REST APIs and SOAP APIs, are among the most common APIs. They act as intermediaries, facilitating communication and data sharing between software applications.

The versatility of web APIs is what makes them so powerful. For example, think about how a weather app on your phone retrieves information from various meteorological databases worldwide – all thanks to these clever tools. To delve deeper into this topic, you can explore different API design methodologies that serve different use cases.

A significant part of modern web development revolves around effectively utilising these APIs. However, don’t be intimidated; with JavaScript libraries such as jQuery, working with web APIs is straightforward and can often address many underlying complexities. JavaScript libraries like jQuery make interacting with web APIs almost seamless by handling many low-level details.

Making sense of HTTP and REST

The World Wide Web uses a protocol that determines the formatting and transmission of messages. It establishes the rules for communication between browsers and servers. Where does REST fit in? Well, Representational State Transfer (REST) is an architectural style used for designing networked applications over HTTP.

You’ll learn more about REST and HTTP below, so stay tuned.

Library-based APIs

If you’ve ever wondered how your computer programs talk to each other, then meet the unsung hero: library-based APIs. These are a set of pre-written code pieces that allow software applications to make use of functionalities already available in system libraries.

A classic example is the Windows API. It’s like an interpreter between software and the Windows operating system, allowing apps to utilise features like window management or file handling without needing developers to write this functionality from scratch.

Why should we care? Well, imagine building a house brick by brick when you could be using ready-made sections instead. That’s what these APIs do; they give programmers a head start by providing access to complex system-level operations.

The benefits continue beyond saving time. Using library-based APIs ensures more consistent behaviour across different applications, as they’re all tapping into the same underlying functionality – it’s like everyone speaking the same language.

Hardware APIs

Think of hardware APIs as the interpreters that let software and hardware converse. They allow programs to interact with devices, opening up vast possibilities.

Let’s take printers. You’re not using a printer manufacturer’s software when you hit ‘Print’ on Microsoft Word, are you? But your document still prints out perfectly. This is possible because printer drivers are hardware APIs provided by manufacturers so that different software can use their devices.

The big deal about hardware APIs

In today’s world, where everything from refrigerators to doorbells is smart, hardware APIs play an even more crucial role. Devices like Amazon Echo or Google Home wouldn’t be half as valuable if they couldn’t control other appliances in your house, right?

All this interoperability magic happens thanks to various protocols and standards (like Zigbee or Z-Wave) and also through hardware APIs. These help ensure seamless interaction between diverse gadgets, turning your humble abode into an automated paradise.

Database APIs: the heart of data-driven applications

Think of a database API as the interpreter between an application and its data storage. It’s like having a personal assistant who knows exactly where you’ve stored your files and fetches them whenever needed.

This interaction allows applications to get data from databases without understanding their underlying structure. Just like asking Alexa to play your favourite song, you don’t need to know where it is stored or how Alexa retrieves it – you just enjoy the music.

At Tyk, for example, we leverage database APIs extensively in our system architecture. But why are these APIs so important?

The importance of database APIs

Above all else, database APIs help streamline application processes by ensuring efficient communication with databases. This efficiency can significantly improve overall app performance. Just think about that fast food drive-thru experience – quick service equals happy customers.

Moreover, using database APIs lets developers work more flexibly with different databases. So, no matter what type of ‘food’ your app needs (or, in this case, data), there’s likely a perfect match out there.

Object remoting APIs

APIs like the ones we use at Tyk have various types and functionalities. But let’s get straight to one type akin to a master puppeteer: object-remoting APIs.

These APIs are like invisible strings connecting marionettes across different stages – they help objects from diverse address spaces or processes communicate effectively. It’s all about seamless interaction.

The structure and functionality of object-remoting APIs

How do object-remoting APIs work? Imagine you’re making calls on your phone, but instead of dialling numbers directly, there’s an operator (think old-school switchboard) directing your call. That’s precisely what object remoting does – it allows method invocation requests from a client object residing in one address space to be forwarded to server objects in different addresses.

A real-world use case

A perfect example can be seen with Java Remote Method Invocation (RMI). Here, remote communication between Java programs is facilitated through methods that act as those invisible strings. So if software components were stand-up comedians on tour, their performances could still make us laugh no matter which city’s stage they’re standing on.

Service APIs

Service APIs are your best bet if you’re looking to break down complex software applications into more minor, more manageable services. They’ve become integral to the microservices architecture because they help create a modular and flexible system.

An API gateway, like Tyk, plays a significant role in this process. These gateways serve as intermediaries that accept client API calls, route requests to the appropriate microservice, and then aggregate the responses before sending them back to the client.

Why is this so important? Imagine assembling a jigsaw puzzle without seeing the picture on each piece. Sounds challenging, right? This is where service APIs come in handy – they give context and structure, which makes it easier for developers to understand how individual services fit together within larger systems.

This doesn’t just make life simpler for developers but also has business benefits. With service APIs and an API gateway for microservices, you can quickly and efficiently update or modify a well-structured application without disrupting other system parts. It’s like replacing one piece of a Lego set rather than rebuilding everything.

Public or open APIs

Public or open APIs let developers interact with software applications. It’s like selecting from a restaurant menu; you make your pick, and the kitchen (application) provides it to you without any hassle.

Companies use these types of APIs for several reasons. One key reason is innovation. By opening up their platforms via APIs, they can invite external developers to create new features and services that add value to their offerings.

Tyk, for instance, uses open APIs extensively. It’s like an ever-evolving digital playground where ideas become realities through coding magic. They increase efficiency, as developers no longer have to begin from the beginning each time. Instead, they can leverage existing functionalities and concentrate on forming unique solutions.

Open APIs also foster community. Open source projects often have passionate communities around them, contributing significantly to product improvement and innovation.

One further benefit is a better customer experience. New integrations mean more options for end-users, who benefit from innovative solutions developed using these accessible tools.

Private or internal APIs

Private or internal, APIs are like hidden doors in a fortress, not seen by all but incredibly beneficial for those aware of their whereabouts and how to take advantage of them.

This type of API is typically used within an organisation, hence its ‘private’ tag. Just as you wouldn’t give strangers free access to your home, these APIs are designed only for trusted users – often developers working on the same project.

The main reason businesses use private APIs is to streamline processes by enabling different parts of their system to talk with each other smoothly. Think about it: things work better when departments communicate effectively in any business scenario.

Internal APIs mean developers can make changes quickly without impacting external systems. Since they’re built internally, they also integrate seamlessly into existing workflows and structures, while with restricted access comes enhanced security. No wonder many companies love using private APIs – they get more done while keeping things under wraps.

Types of APIs based on technology


We recently explored types of API protocols in depth, but it’s worth looking at the headline details here about API technology types, too. Let’s look at RESTful APIs first, as APIs that employ the REST protocol are the most common.

1. Principles and characteristics

REST APIs are lightweight, stateless and versatile, with communication taking place over HTTP/HTTPS.

2. Advantages and use cases

RESTful APIs are highly scalable with cacheable responses. This makes them ideal for businesses with significant growth plans looking for powerful performance.


SOAP APIs are often viewed as legacy products, as modern businesses use newer API protocols, such as REST.

1. Structure and characteristics

The SOAP web service protocol uses XML data formatting. SOAP APIs define message structures and processing details within envelopes. They are extensible, operationally flexible and language-independent.

2. Advantages and use cases

SOAP provides plenty of flexibility, operating over HTTP, UDP, TCP, SMTP and JMS, while SOAP APIs are both language- and platform-independent. Their robust security makes them well-suited to large corporate operations such as banks and government departments – though modern institutions may find that REST or GraphQL APIs better suit their needs.

GraphQL APIs

GraphQL APIs use fields and arguments to fetch data and compile the results, reducing the number of requests required and delivering greater efficiency.

1. Concept and characteristics

APIs created using the GraphQL specification work with a schema that describes the data, providing the ability to evolve the schema over time rather than the API, reducing the risk of breaking changes. They offer a range of batching techniques for greater efficiency.

2. Advantages and use cases

GraphQL APIs are well suited to businesses looking for fast, agile, powerful performance that’s easy to scale.


Websockets are not APIs. They are a bidirectional communication protocol that enables a real-time connection between clients and servers, meaning they can be an essential part of an API architecture.

1. Functionality and characteristics

WebSockets facilitate real-time data exchange by establishing persistent connections that last as long as needed. By combining them with (for example) RESTful APIs, you can create an architecture that supports real-time, low-latency communication while handling standard HTTP-based interactions.

2. Advantages and use cases

Low latency, real-time, and bidirectional communication are critical advantages of Websockets, making them handy for platforms and apps that benefit from these features. Chat apps, stock market apps, business collaboration tools, multiplayer gaming experiences… all and more can benefit from WebSockets.

The power of APIs

Unravelling the maze of APIs is no small feat. We’ve traversed the vast landscapes of different types of API, each with its unique strengths and use cases.

We’ve journeyed far from web APIs’ bustling highways to library-based APIs’ systematic streets. But there’s always more to explore in this dynamic world.

We peeked at hardware APIs and sifted through data goldmines using database APIs. Remember how object remoting and service APIs broke down barriers between software components?

The power APIs wield in shaping our digital interactions is awe-inspiring. If you’re keen to harness that power, it’s important to do so strategically. Check out our free API strategy success kit for everything you need to know.