What is an API in simple terms?

It's the 'service window' a system offers so other programs can read or write data automatically, without human intervention. If a system has a documented API, it can connect with your ERP, your dashboards or your automations; if it doesn't, moving data requires manual work.

What's the difference between an API and a webhook?

The API responds when asked (another system queries 'give me today's sales'). The webhook notifies on its own initiative when an event occurs ('a new order came in'). They complement each other: the API for querying and loading data, webhooks for reacting in real time.

What can you do if a system has no API?

There are alternatives with varying robustness: scheduled automatic exports, direct database reads when the vendor allows it, or screen automation (RPA) as a last resort. All work, but they're more fragile than a documented API — which is why API-first systems should be prioritized when choosing software.

Integrations

APIs Explained for Business People: How Your Systems Talk to Each Other (No Magic)

Okun Data Team · June 24, 2026 · 5 min read

"Does the system have an API?" is probably the most important question asked (or forgotten) when buying any software. On the answer depends whether your systems connect to each other automatically — or whether someone on your team spends years downloading Excels from one system to upload into another. This article explains the concept without technicalities, so you can take part in those decisions with your own judgment.

What an API is, in one analogy

An API is a system's service window for other systems. Just as a human customer uses the screens, another program uses the API: it asks "give me today's sales" or instructs "load this invoice", and the system responds in a format machines understand. Without that window, the only way to get data in or out is for a person to do it by hand through the screens.

When a vendor says "our system has an API", they're saying: other systems will be able to read and write data here automatically. That sentence is worth money: it determines whether your ERP can feed your dashboards on its own, whether your e-commerce can invoice without retyping, whether your data stack can refresh nightly without human intervention.

Webhooks: the API that calls you

The classic API works on demand: you have to ask it. A webhook is the reverse mechanism — the system notifies you when something happens: "a new order came in", "the payment was approved". Instead of asking every five minutes whether there's news, the news finds you. For real-time automations (alerting the warehouse the moment a sale lands), it's the key piece.

The questions to ask before signing

"Does it have an API? Is it publicly documented?" — If the documentation is secret or "on request", bad sign.
"What data does it expose?" — Some systems' APIs only let you read customers but not sales, or read but not write. The detail matters.
"Does it cost extra?" — Some vendors charge separately for API access, or reserve it for the enterprise plan. Better to know beforehand.
"Are there usage limits?" — APIs usually cap requests per minute. Fine for normal use; for massive migrations you need to plan.
"How do I export ALL my data if I leave?" — The divorce question. If there's no clear answer, you're evaluating a safe only the vendor can open.

What if the system has no API?

Not all is lost — there's a plan B with a clear hierarchy: scheduled automatic exports (acceptable), direct database reads if the vendor allows it (good option on-premise), or screen automation/RPA as a last resort (fragile: it breaks with every redesign). In automation projects we use this whole toolbox — but when the client gets to choose software, the recommendation is always the same: with a documented API.

Conclusion

You don't need to know how to code to make good integration decisions: you need to ask five questions at the right time. Systems with open APIs integrate, automate, and let you leave; closed ones create copy-paste jobs and vendor dependence. Next time you evaluate software, let the machine-facing window weigh as much as the human-facing screens.

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Frequently asked questions

What is an API in simple terms?: It's the 'service window' a system offers so other programs can read or write data automatically, without human intervention. If a system has a documented API, it can connect with your ERP, your dashboards or your automations; if it doesn't, moving data requires manual work.
What's the difference between an API and a webhook?: The API responds when asked (another system queries 'give me today's sales'). The webhook notifies on its own initiative when an event occurs ('a new order came in'). They complement each other: the API for querying and loading data, webhooks for reacting in real time.
What can you do if a system has no API?: There are alternatives with varying robustness: scheduled automatic exports, direct database reads when the vendor allows it, or screen automation (RPA) as a last resort. All work, but they're more fragile than a documented API — which is why API-first systems should be prioritized when choosing software.