What It Is
An API, short for application programming interface, is a doorway that lets two software systems talk to each other. Think of a waiter in a restaurant. You do not walk into the kitchen; you give your order to the waiter, who brings back what you asked for. An API works the same way. Your website sends a request in an agreed format, and another service, such as a payment processor or a map, sends back a response.
Why It Matters for Your Business
For a small business, APIs are what let your tools work together. When your website shows live Google reviews, takes card payments through a payment service or adds a new contact to your email list, an API is usually doing the work. A contractor’s quote form could send each lead straight into a CRM through its API, so nobody has to retype it.
Good to Know
Common mistake: assuming every tool can connect to every other tool. Before you buy software, check whether it offers an API or a ready-made integration with the systems you already use. Also keep any API keys (the passwords these connections use) private, because anyone holding them may be able to act on your account.