Backward compatibility is the property that a newer version of a system still works with things made for an older version. A new API release that keeps accepting old requests, or a new app version that opens files created by earlier ones, is backward compatible.
Why it matters
Clients, integrations and stored data often cannot be updated at the same moment as the server. Breaking compatibility can cause outages for every consumer of an API. Teams preserve it by adding fields instead of changing them, deprecating before removing and publishing versioned endpoints.
Example
Adding a field is usually safe:
{"id": 42, "name": "Asha", "plan": "free"}An old client that reads only id and name keeps working. Renaming name to full_name is a breaking change, because that client now finds nothing under the key it expects.
Common mistakes
- Changing the type or meaning of an existing field and calling it a minor update.
- Removing an endpoint without a deprecation period.
- Confusing it with forward compatibility, where an old version can handle data from a newer one.
Related
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यह पेज सामान्य जानकारी है, जिसे हमारी संपादकीय टीम ने लिखा है और दस्तावेज़ीकरण बदलने पर अपडेट किया जाता है। सर्वर और प्रदाता अलग-अलग होते हैं, इसलिए बदलाव पहले सुरक्षित तरीके से जाँचें। देखें: संपादकीय नीति और अस्वीकरण.