What's an API?
An API is a way for two computer systems to communicate with each other. The letters stand for Application Programming Interface. An API allows a service or data to be available to users, generally outside the company offering the API. To take flood data as an example, an insurance company may receive requests for insurance quotes. The insurance company receives an address and would like to determine the quote to offer. The insurance company's software can send the address to National Flood Data automatically. The National Flood Data API receives the address, uns a process within National Flood Data to determine the flood zone and then returns that data to the insurance company.
Why API's are important?
An API may sound technical and the formal description may look complicated, but they are very efficient and follow conventions that make them quick and easy to use. Using an API can save an enormous amount of time. Rather than communicating by email, for example, two software systems can communicate automatically. Insurance companies are turning more and more to software for things like flood data to make their work more efficient, and APIs are a key part of this.