Controls are fundamentally a set of parameters that control how the user moves around in the timeline and how the scene is played back. This set of parameters is contained in the Play Control property set (its scripting name is PlayControl). Some of the most useful parameters include:
Current: Contains the current frame number (see Getting and Changing the Current Frame).
In and Out: Contain the first and last frame numbers (see Moving Around in the Timeline).
Step: Sets the interval at which frames are played back in the viewport. A value of 2 causes the viewports to display only every second frame in the viewport during playback.
Format and Rate: Control the frame rate for the PAL, NTSC, Film, and HDTV formats (see Controlling the Frame Rate and Format for more information).
KeepFrameTiming: Determines whether to save fcurve keys in frames (relative) or seconds (absolute).
OnFrameChangeCommand: Allows you to run simple VBScript code each time the frame changes (see Running Commands During Playback at Each Frame Change for more information).
PlayControl does not have a special class implemented in the object model or C++ API. Most functionality is available via scripting commands, but you can also access it in the object model and the C++ API like any other Property or Property object, which is demonstrated in Accessing the PlayControl Property Set.