An API is a software component, that facilitates digital products and services to communicate and interact with each other in order to share data. APIs are used in server-based B2B products, like Salesforce, as well as in everyday B2C smartphone apps, like weather forecasts.
Let’s understand what does API mean in programming, how it works, and what are its benefits with examples.
What Does API Mean in Programming?
An application programming interface (API) is a set of rules that enables a software program to transmit data to another software program. APIs enable developers to avoid redundant work; instead of building and rebuilding application functions that already exist, developers can incorporate existing ones into their new applications by formatting requests as the API requires.
An API is an “interface,” meaning a way for one thing to interact with another. As a real-world example, an ATM has an interface — a screen and several buttons — allowing customers to interact with their bank and request services, like getting cash. Similarly, an API is how one piece of software interacts with another program to obtain needed services.
Let’s consider an example. Imagine ‘X’ builds a website that helps commuters check highway traffic before they leave for work. ‘X’ could spend a lot of time and money setting up a complex highway tracking system to provide this information to her website’s users. But these capabilities already exist, as outside parties have created such systems. Instead of reinventing the wheel in this way, ‘X’s’ website uses an API that is offered by an external highway tracking service. Now ‘X’ can focus on building other aspects of the website.
How Do APIs Work?
APIs are made up of two related elements.
- Specification: It describes how information is exchanged between programs, done in the form of a request for processing and a return of the necessary data.
- Software Interface: It’s written to that specification and published in some way for use.
The software that wants to access the features and capabilities of the API is said to “call” it, and the software that creates the API is said to “publish” it.
APIs authorize and grant access to data that is requested by users and other applications. Access is authenticated to a service or portion of functionality, against predefined roles that govern who or what service can access specific actions or data. APIs also provide an audit trail that details system access: who or what, and when.
Applications that call APIs were traditionally written in specific programming languages. Web APIs can be called through any programming language, but can also be accessed by webpages created in HTML or application generator tools.
What is an API Call?
Application programming interfaces (APIs) are a way for one program to interact with another. API calls are the medium by which they interact. An API call, or an API request, is a message sent to a server asking an API to provide a service or information.
If ‘X’ is hosting a lot of guests for dinner, he might call a catering company and ask that they prepare food for the party. This saves him a great deal of time and effort preparing food himself. Similarly, one application can “call” another for needed data or functionality. This ensures developers do not have to spend time and effort building application capabilities that can be integrated via API.
Because APIs are integrated into almost all web applications today, API calls take place behind the scenes all the time. Suppose someone searches for bus tickets on a travel website. The travel website sends an API call to the various bus companies’ servers and receives back information about what rides are available and how much they cost. From the user’s perspective, this process should be almost instantaneous.
Where Does an API Call Go?
API calls travel from a client to an API endpoint. API endpoints are the places that API calls go to — most often, a web application and a server. A mobile client, for example, generates an API call that goes to the API endpoint, a server. The server receives the API call, processes it, executes the request, and sends a response.
When ‘X’ (from the analogy above) calls the catering company, he does so by dialing a phone number. Similarly, API calls are directed at a uniform resource identifier (URI).
A URI is a standardized way to identify a resource, just as a phone number identifies a phone line. The identified resource could be a website, an application, a server, an email contact, or even a real-world item.
For web APIs, typically the URI is a uniform resource locator (URL). A URL is a type of URI for identifying Internet locations like a website or a server. A URL has to include the application layer protocol, such as HTTP, used to reach it. Most web APIs use HTTP, so that is included in the API endpoint’s URL.
What are the Benefits of Using APIs?
APIs are basically a set of rules. They improve an organization’s internal development processes by standardizing how developers write application code — using the same rules and formats makes code more streamlined and transparent. Standardization also facilitates collaboration between developers as they build software components with the intent to integrate with APIs. This, in turn, can support feature development and reduce time to market.
APIs enable organizations to:
- securely control and manage how users and systems access specific data and service functionality
- allow third parties to leverage their data (even in a limited sense), which increases a company’s brand exposure
- grow their customer database and even increase their conversion rate by aligning their services with other trusted brands; monetize their APIs so that they become a distinct line of revenue
Types of APIs
There are four basic types of APIs – private, public, partner, and composite.
- Private APIs, or internal APIs, are published internally for use by the company’s developers to improve its own products and services. Private APIs are not exposed to third parties.
- Public APIs, or open APIs, are published publicly and can be used by any third party. There are no restrictions on these APIs.
- Partner APIs can only be used by specific parties with whom the company agrees to share data. Partner APIs are used within business relationships, often to integrate software between partnering companies.
- Composite APIs combine multiple APIs to address related or interdependent tasks and often improve speed and performance compared with individual APIs.
APIs may be further classified as local, web, or program APIs.
- Local APIs offer OS or middleware services to application programs. Microsoft’s .NET APIs, the TAPI (Telephony API) for voice applications, and database access APIs are examples of the local API form.
- Web APIs are designed to represent widely used resources such as HTML pages and are accessed using a simple HTTP protocol. Any web URL activates a web API. Web APIs are often called RESTful because the publisher of REST interfaces doesn’t save any data internally between requests. As such, requests from many users can be intermingled as they would be on the internet.
- Program APIs are based on remote procedure call (RPC) technology that makes a remote program component appear to be local to the rest of the software. Service-oriented architecture (SOA) APIs, such as Microsoft’s WS series of APIs, are program APIs.
Practice Problems
- API is a
- Software
- Hardware
- Both software and hardware
- Either software or hardware
- API is an acronym for
- Application Programming Interchange
- Asynchronous Programming Interchange
- Application Programming Interface
- Asynchronous Programming Interface
- The medium by which API interact are called
- API calls
- API requests
- API interchange
- API action
FAQs
What does API stand for?
API is an abbreviated form of Application Programming Interface. It is a set of rules that enables a software program to transmit data to another software program.
What is the function of API?
APIs help
a) to securely control and manage how users and systems access specific data and service functionality
b) third parties to leverage their data (even in a limited sense), which increases a company’s brand exposure
c) grow their customer database and even increase their conversion rate by aligning their services with other trusted brands; monetize their APIs so that they become a distinct line of revenue
What is an API Call?
Application programming interfaces (APIs) are a way for one program to interact with another. API calls are the medium by which they interact. An API call, or an API request, is a message sent to a server asking an API to provide a service or information.
Conclusion
An application programming interface (API) is a set of rules that enables a software program to transmit data to another software program. APIs facilitate digital products and services to communicate and interact with each other in order to share data. It helps to securely control and manage how users and systems access specific data and service functionality.
