SDK

Software Development Kit

Pre-built libraries and tools for building on a platform.

When you'd see it: Integrations and vendor evaluations. "They have an SDK for that" means there is pre-built code for working with a service.

Why it matters: An SDK is a packaged set of tools and code that makes building on a platform faster than calling its raw API. The quality of a vendor's SDK is a real factor in how painful the integration will be.