Conventions Used in This Book

This book uses the following abbreviations:

Hz, kHz, MHz, and GHz

Hertz (cycles per second), KiloHertz (one thousand Hertz), MegaHertz (one million Hertz), and GigaHertz (one billion, or 109 Hertz).

bps, Kbps, Mbps

Bits per second, kilobits (1024 bits) per second, and megabits (1,048,576 bits) per second.

KB/s, MB/s

Kilobytes (1024 bytes) per second and megabytes (1,048,576 bytes) per second.

This book uses the following typographic conventions:

Constant width

Constant width is used for listing the output of command-line utilities and for command names.

Constant width italic

Constant width italic is used to show items that need to be replaced in commands.


Italic is used for emphasis, for first use of a technical term, and for example URLs.


Ellipses indicate text that has been omitted for clarity.

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This icon indicates a warning or caution.