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What is an Application Programming Interface (API)
Application programming interfaces (APIs) are the unsung heroes of the digital world. Everything we do online demands connectivity – across devices, networks, applications, countries,and even satellites. APIs are the invisible widgets that make those connections happen.
In technical terms, they’re vital bits of software that use standard protocols, routines, function, and commands to facilitate data transfer between machines and programs.
Think of them as computing chaperones, making introductions between systems, agreeing arrangements, then confirming everything with a virtual handshake. Let’s dig into how they work.
Key takeaways
- APIs are one of the technical cornerstones of digital transformation.
- By facilitating connections, they allow our deeply integrated ecosystem of devices, app, and databases to work together.
- APIs come in different forms, but today, most are designed for the web.
- There are drawbacks. APIs pose security challenges and sometimes raise compatibility issues.
- All in all, they keep the digital economy running, invisible but irreplaceable.
How Do APIs Work?
You may not realize it, but you’re using an application programming interface right now. When you loaded this web page into your browser, the browser sent a request to an API seeking access to the site.
The API assessed it and responded positively, giving the green light for the website to draw text and image information from our database. The API had to check first and make sure your browser was using the correct standards, permission, and protocols before saying yes or no to the exchange of data. It did this using an API key, a unique code that identified and authenticated you or the application you used.
To you (and us), the API calls, sharing of keys, and overall data exchange all happened instantly and seamlessly.
Four Types of APIs
APIs are usually grouped together by use case. There are APIs for data, operating systems, devices, and the web:
- Data APIs are used to facilitate connections between databases and applications.
- Operating system (OS) APIs define how apps can use operating system services and resources.
- Remote APIs control how applications running on different devices can connect and interact.
- Web APIs allow data and functionality to move back and forth via the Internet.
Given the growth of cloud and SaaS software, most APIs today are web APIs and use an architecture designed to work with hypertext transfer protocol (HTTP).
API Protocols
As web APIs have come to dominate the field, five HTTP-friendly protocols have moved to the forefront:
APIs vs. Webhooks
APIs and webhooks play a similar role in computing. Though both technologies allow different systems to communicate and share data with one another, there’s a distinction in how they operate.
Sometimes called ‘event-based APIs,’ webhooks are automatic responses written into software. If a user or application does something specific (the ‘event’), it triggers the webhook to execute an automatic response.
An API relies on request-driven interactions, where a user or application makes a request to another application and then receives a response.
While a webhook sends data to other applications, an API draws data after making a request.
API Examples
APIs you’d be likely to encounter frequently include:
API Use Cases in Different Industries
Given the ongoing shift to working, shopping, playing, and communicating online, APIs play a vital role in the digital economy.
One practical example is the synchronization of order management systems in manufacturing. By using APIs to connect back office and factory systems, managers can automate data flows so that actions around order placement and fulfillment are instantly reflected in inventory systems.
Another example is the control of smart devices in the hospitality sector. APIs connect point-of-sale (POS) systems with the mobile apps used by servers and front-of-house staff. This allows restaurant and event businesses to instantly update pricing and display targeted promotions or advertisements through their mobile apps.
API Trends
Recent trends and advances in API technology point to their growing importance as a cornerstone of digital business.
For example, with the number of applications used by businesses growing every year, companies are increasingly using open APIs from outside developers. Because they are designed to work with a wide variety of systems, they enable functionality and data more effectively than APIs written internally.
As business applications offer more discrete functionality, there is also a trend to unbundle API capabilities. An organization might, for example, buy a comprehensive API suite for most of the functionality it requires, adding a specialized API designed for developer portals.
API Pros and Cons
Like any technology, APIs have advantages and disadvantages.
- APIs enable different systems to communicate back and forth, regardless of platform or underlying programming language.
- APIs let third-party developers build apps that integrate easily with other software systems, delivering a better user experience (UX).
- APIs give developers more choice over programming languages and frameworks, allowing them to choose the best technical tools for their needs.
- APIs can allow companies to create new revenue streams by giving third-party developers access to their applications and data.
- APIs can have security weaknesses that make them vulnerable to SQL injection and cross-site scripting (XSS) attacks.
- APIs can require a significant amount of development effort to implement and maintain.
- APIs can cause errors and even lead to system failures due to compatibility issues between different systems.
- APIs often need third-party developers to write additional software that enables integration.
- APIs need to be included in IT and data governance rules to ensure they are being used correctly and consistently.
The Bottom Line
Despite a few concerns, it’s hard to find fault with application programming interfaces. By definition they deliver an easy way for disconnected systems and devices to interface. End users get a seamless digital experience, and businesses get simplified application and software development.
APIs give application owners a simple, secure way to make their data and functionality available to other applications, other departments inside the same company, or supply chain partners. That means more innovation, collaboration, and new opportunities to monetize data.
