| No. | Item | Definition |
|---|---|---|
| 1. | API | application programming interface |
| 2. | authentication | verifying identity of a caller |
| 3. | authorization | granting allowed access rights |
| 4. | availability | time a service is usable |
| 5. | backoff | increasing delay between retries |
| 6. | bandwidth | data transfer capacity |
| 7. | body | main content of a message |
| 8. | bug | software defect |
| 9. | cache | stored data for faster reuse |
| 10. | circuit breaker | stops calls during repeated failures |
| 11. | client | software consuming an API |
| 12. | compatibility | ability to work across versions |
| 13. | consistency | uniform data across reads |
| 14. | contract | agreed interface behavior |
| 15. | CORS | browser cross-origin access rules |
| 16. | cursor | position marker for pagination |
| 17. | database | organized persistent data store |
| 18. | debugging | finding and fixing problems |
| 19. | deployment | releasing software to environments |
| 20. | deprecation | marking a feature for removal |
| 21. | documentation | written explanation of usage |
| 22. | downtime | time system is unavailable |
| 23. | encryption | scrambling data for protection |
| 24. | endpoint | specific API URL or route |
| 25. | environment | specific runtime setup |
| 26. | error | problem preventing success |
| 27. | escaping | making special characters safe |
| 28. | event | notable occurrence in a system |
| 29. | filter | condition narrowing returned data |
| 30. | gateway | entry point managing API traffic |
| 31. | governance | rules guiding API management |
| 32. | GraphQL | query language for APIs |
| 33. | handshake | initial exchange establishing communication |
| 34. | hashing | one-way data transformation |
| 35. | header | metadata sent with HTTP messages |
| 36. | HTTP | web transfer protocol |
| 37. | HTTPS | secure HTTP over TLS |
| 38. | idempotent | safe to repeat without change |
| 39. | identifier | value uniquely naming something |
| 40. | integrity | correctness and wholeness of data |
| 41. | JSON | lightweight data interchange format |
| 42. | key | value used in cryptography |
| 43. | latency | delay before a response |
| 44. | lifecycle | stages from design to retirement |
| 45. | load balancing | distributing traffic across servers |
| 46. | logging | recording events and messages |
| 47. | method | HTTP action like GET or POST |
| 48. | metrics | measured performance values |
| 49. | middleware | software between request and handler |
| 50. | migration | structured change to schema |
| 51. | mock | simulated API behavior |
| 52. | monitoring | tracking system health and behavior |
| 53. | namespace | named context avoiding collisions |
| 54. | OAuth | delegated authorization framework |
| 55. | observability | ability to inspect system state |
| 56. | OpenAPI | standard API description format |
| 57. | pagination | splitting results into pages |
| 58. | parameter | named input to an operation |
| 59. | path | URL segment identifying location |
| 60. | payload | data sent in a message |
| 61. | permission | allowed action or access |
| 62. | production | live environment for users |
| 63. | protocol | rules for communication |
| 64. | proxy | intermediary forwarding requests |
| 65. | query | URL parameters after question mark |
| 66. | queue | ordered list of pending messages |
| 67. | quota | fixed usage allowance |
| 68. | rate limit | maximum requests allowed |
| 69. | request | client call to a server |
| 70. | resilience | ability to recover from issues |
| 71. | resource | entity exposed by an API |
| 72. | response | server reply to a request |
| 73. | REST | resource-oriented web API style |
| 74. | retry | attempting a failed call again |
| 75. | RPC | remote procedure call style |
| 76. | schema | structured definition of data |
| 77. | search | finding matching resources |
| 78. | serialization | converting data to transferable form |
| 79. | server | software providing an API |
| 80. | SOAP | XML-based messaging protocol |
| 81. | sort | ordering returned results |
| 82. | stateless | not storing client context |
| 83. | status code | numeric HTTP result indicator |
| 84. | stream | continuous flow of data |
| 85. | test | check that behavior is correct |
| 86. | throttling | slowing requests to control load |
| 87. | throughput | amount processed over time |
| 88. | timeout | maximum wait before failure |
| 89. | TLS | protocol securing network traffic |
| 90. | token | credential used for access |
| 91. | tracing | following requests across services |
| 92. | transaction | all-or-nothing data operation |
| 93. | uptime | time system stays operational |
| 94. | UUID | universally unique identifier |
| 95. | validation | checking input against rules |
| 96. | versioning | managing API changes over time |
| 97. | webhook | HTTP callback triggered by events |
| 98. | websocket | persistent two-way web connection |
| 99. | workflow | sequence of connected steps |
| 100. | XML | markup-based data format |