SCSI命令集旨在通过操作系统对输入/输出设备（磁盘、磁带、打印机等）提供高效的对等操作。SCSI命令集采用命令响应协议。在收到响应之前，对SCSI命令的操作不得视为已完成。响应应包括指示命令最终处置的状态。 SCSI命令集提供对一个或多个输入/输出设备的多个操作系统并发控制。但是，多个操作系统必须正确协调它们的操作，否则将导致数据损坏。 本标准规定了SCSI的功能要求- 3个流命令（SSC）。SSC 允许SCSI流设备（如磁带和打印机设备）连接到计算机和 提供其使用的定义。 本标准规定了设备服务器的外部行为，该服务器将自身定义为 顺序存取设备或打印机设备；这些设备类型统称为流设备。 SSC标准 符合SCSI-3体系结构模型（ISO/IEC 14776-411:1999）标准。

The SCSI command set is designed to provide efficient peer-to-peer operation of input/output devices (disks, tapes, printers, etc.) by an operating system. The SCSI command set assumes a command-response protocol. Action on SCSI commands shall not be deemed completed until a response is received. The response shall include a status that indicates the final disposition of the command. The SCSI command set provides multiple operating systems concurrent control over one or more input/output devices. However, the multiple operating systems must properly coordinate their actions or data corruption will result. This standard specifies functional requirements for SCSI-3 Stream commands (SSC). SSC permits SCSI streaming devices such as tape and printer devices to attach to computers and provides the definitions for their use. This standard specifies the external behavior of a device server that defines itself as either a Sequential-access device or a Printer device; together, these device types are known as Stream Devices. The SSC standard conforms to SCSI-3 Architectural Model (ISO/IEC 14776-411:1999) standard.