CyberSource refers to the APIs and SDKs used to integrate with the CyberSource payments platform.
CyberSource is a global payments platform. CyberSource provides payment management APIs and language-specific libraries wrapping their API.
CyberSource provides server-side libraries for .NET, PHP, Python, Ruby, Java, and Node.js, as well as mobile SDKs for iOS and Android.
Questions tagged with cybersource should be questions regarding one of these libraries or APIs.