A "MoCap Pack" is a set of 3D character animations used for game development and 3d production. The animations were recorded by a live actor using motion capture giving the character's movement a realistic, life-like, human feel. They were created as an .FBX animation files and ported fur use in Unreal Engine, Unity3D, Blender, & iClone, as well as .BIP file format. The animations have been professionally edited and many connect in combination allowing the character to transition between different movements.
A MoCap Pack could include things like Standing, Walking, Jogging, and Running; with Starts, Stops, and Turns in multiple directions.
Each animation has been carefully edited and pose-matched to create seamless loops and transitions to the other animations in the pack.
*These packs are not "code"; a programmer typically uses them to populate animation controllers.