# About Terminology

The general terms “device” and “host” are used in different, often incompatible ways in a multitude of specifications and contexts. For instance, the term "host" can signify different things depending on the context—such as USB communication versus networked financial transaction processing. In this document, "device" and "host" are defined specifically as follows:

* **Device** refers to the Secure Card Reader Authenticator (SCRA) or PIN Entry Device (PED) that receives and responds to the command set specified in this document. Refer to **Table 3 - Device Features**, to determine a device’s specific capabilities; not all devices support PIN entry. Devices include DynaFlex, DynaProx, DynaFlex II, and so on.
* **Host** refers to the piece of general-purpose electronic equipment the device is connected or paired to, which can send data to and receive data from the device. Host types include PC and Mac computers/laptops, tablets, smartphones, teletype terminals, and even test harnesses. In many cases the host may have custom software installed on it that communicates with the device. When “host” must be used differently, it is qualified as something specific, such as “acquirer host” or “USB host.”

Similarly, the word “user” is used in different ways in different contexts. This document separates users into more descriptive categories:

* The **cardholder**
* The **operator** (such as a cashier, bank teller, customer service representative, or server)
* The **developer** or the **administrator** (such as an integrator configuring the device for the first time)

Because some connection types, payment brands, and other vocabulary name spaces (notably Bluetooth® LE, EMV, smart phones, and more recent versions of Windows) use very specific meanings for the term “Application,” this document favors the term **host software** to refer to software on the host that provides a user interface for the operator.

The combination of device(s), host(s), host software, device firmware, device configuration settings, physical mounting and environment, user experience, and documentation is referred to as the **solution**.


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