The term SDK stands for:
Software development kit
SDK or Software Development Kit Describes a software development environment or set of libraries consisting of a programming language, a runtime environment and a compiler as well as program libraries. SDKs in the blockchain frameworks exist for Corda (e.g., Tokens SDK), Ethereum (e.g., OpenZeppelin SDK) or Hyperledger (e.g., Fabric SDK). SDK is a well known term in tech because many environments or operating systems include SDK libraries such as Android SDK, iOS SDK etc
More Abbreviatons