Business analysis glossary
API (Application Programming Interface)
What it is
An API is a defined way for one piece of software to ask another to do something or provide data, without knowing how it works inside. It specifies what can be requested and what comes back. The party that offers the API is the provider, and the party that uses it is the consumer; a clear description lets both work independently.
Why it matters
Modern systems are connected through APIs. Analysts write requirements about what data flows between systems, so they need to understand what an API can and cannot provide. An analyst who understands APIs can ask sharper questions, such as what happens if the payment provider is slow or the response is empty.
Example
When a customer pays at Marlow Online Store, the shop software calls the payment provider's API with the amount and order number. The provider replies saying whether the payment succeeded. The shop never sees the provider's internal systems; it just sends a defined request and reads the answer, which keeps both sides simple.