# Portfolio Items

This chapter provides lists of item types and system items. The following table is a brief description of each item.

- `Attachment` The binding of a sample or an envelope to an instrument.
- `Bitmap` Frame buffer into which rendering may be performed.
- `Cue` Audio cue item.
- `Envelope` Audio envelope.
- `ErrorText` A table of error messages.
- `File` A handle to a data file.
- `File alias` A character string for referencing the pathname to a file or a directory of files.
- `Folio`A family of function calls.
- `Instrument` DSP instrument item.
- `IOReq` An item used to communicate between a task and an I/O device.
- `Knob` An item for adjusting an instrument's parameters.
- `Locale` A database of international information.
- `Message` The means of sending data from one task to another.
- `Message port` An item through which a task receives messages.
- `Probe` An item to permit the CPU to read the output of a DSP instrument.
- `Sample` A digital recording of a sound.
- `ScreenGroup` A collection of one or more screens.
- `Semaphore` An item used to arbitrate access to shared resources.
- `Task` A process.
- `Template` A description of an audio instrument.
- `Tuning` An item that contains information for tuning an instrument.
- `VDL` A display control object.