A VST Plug-in is an audio processing component that is utilized within a host application. This host application provides the audio or/and event streams that are processed by the Plug-in's code. Generally speaking, a VST Plug-in can take a stream of audio data, apply a process to the audio, and return the result to the host application. A VST Plug-in performs its process normally using the processor of the computer. The audio stream is broken down into a series of blocks. The host supplies the blocks in sequence. The host and its current environment control the block-size. The VST Plug-in maintains the status of all its own parameters relating to the running process: The host does not maintain any information about what the Plug-in did with the last block of data it processed. From the host application's point of view, a VST Plug-in is a black box with an arbitrary number of inputs, outputs (Event (MIDI) or Audio), and associated parameters. The host needs no implicit knowledge of the Plug-in's process to be able to use it. The Plug-in process can use whatever parameters it wishes, internally to the process, but depending on the capabilities of the host, it can allow the changes to user parameters to be automated by the host.