API
Application Programming Interface
Simple Explanation
An API is a way for two different computer systems to communicate with each other. Imagine you're in a restaurant. You tell the waiter what you want to eat. The waiter takes your request to the kitchen and brings back the food when it's ready. An API works in a similar way. One computer system sends a request to another system, and the API provides an agreed way to ask for information or an action and receive a response. This happens behind the scenes in many websites and apps.
Technical Explanation
An Application Programming Interface (API) is a defined set of rules that allows software systems to request information or services from one another. It specifies how requests and responses are structured, allowing systems to communicate without needing direct access to each other's internal workings.
Business Use Case
An online retailer sells products through its website. When a customer places an order, the retailer needs to arrange payment and delivery. The website uses an API to communicate with a payment provider and another API to communicate with a delivery company. The payment provider confirms whether the transaction succeeded, while the delivery service can return shipping information. This allows the retailer to connect different business services without building every system itself.
Real-Life Example
Imagine Michael opens a weather app before going for a walk. He wants to know whether it will rain in the next hour. The weather app uses an API to request forecast information from a weather service. The service sends the information back, and the app displays it on Michael's phone. Michael sees that rain is expected and decides to take an umbrella.
A weather app requests forecast information from a weather service through an API, and the forecast information is returned to the app, where Michael sees that rain is expected.