Key Terms to Know Before You Start Building Alexa Skills

Want to get started with the Alexa Skills Kit (ASK)? Check out this quick summary of the most commonly used terms before you start building your first Alexa skill.

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View our full glossary of ASK terms.


Alexa skill

A set of actions or tasks that are accomplished by Alexa. Skills are like apps for Alexa, helping customers perform everyday tasks or engage with your content naturally with voice. Alexa provides built-in functionality, such as timers and alarms. You can use the Alexa Skills Kit to create skills for Alexa. A skill includes both the code, in the form of a cloud-based service, and the configuration provided on the developer console.

Alexa device

A device that provides access to the Alexa service. Examples include Amazon Echo, Amazon Echo Dot, Amazon Tap, Echo Show, and devices made by other manufacturers that use the Alexa Voice Service.

Alexa Skills Kit

A collection of APIs, tools, and documentation for giving Alexa new capabilities. See Build Skills with the Alexa Skills Kit.

automatic speech recognition (ASR)

A technology that converts spoken words into text. ASR is the first step in enabling technologies like Alexa to respond when you ask, "Alexa, what's it like outside?“


custom skill

A skill that uses a custom interaction model. You define the requests your skill can handle (intents) and the words customers say to make (or invoke) those requests (sample utterances). The mapping between the intents and sample utterances creates the interaction model or voice user interface for the skill.


developer console

A development tool that provides a streamlined experience to help you create, manage, and publish Alexa skills.



A representation of the action that fulfills a customer's spoken request. Intents can have further arguments called slots that represent variable information. For example, "Alexa, ask History Buff what happened on June third." In this statement, "…what happened on June third" maps to a specific intent that can be handled by a particular Alexa ability. This tells Alexa that the user wants the skill History Buff to get historical information on a specific date.

For details about defining intents, see Create Intents, Utterances, and Slots.

interaction model

A defined set of logic parameters for your skill that will determine the voice interface through which customers will interact with your skill as well as map customers' spoken input to the intents your cloud-based service can handle.


The act of beginning an interaction with a particular Alexa ability. For example, if a customer wants to wake Alexa to use the Horoscope skill, "Alexa, ask Horoscope for today's reading."

Alexa then follows up after the invocation and asks, "What horoscope sign would you like?"

Types of invocations include: full intent invocationpartial intent invocation, and no intent invocation.


natural language understanding (NLU)

A technology that helps computers deduce what speakers actually mean, not just what words they say. NLU makes it possible for Alexa to infer, for example, that you're asking for a local weather forecast when you ask, "Alexa, what's it like outside?"



An argument to an intent that gives Alexa more information about that request. For example, "Alexa, ask History Buff what happened on June third." In this statement, "…June third" is the value of a date slot that refines the request. For a given intent, slots can be required or optional. To designate slots as required and let Alexa manage the conversation to collect the slot values, create a dialog model and then delegate the dialog to Alexa.

Speech Synthesis Markup Language (SSML)

A markup language that provides a standard way to mark up text to generate synthetic speech. The Alexa Skills Kit (ASK) supports a subset of tags defined in the SSML specification.


text-to-speech (TTS)

Converts a string of text to synthesized speech (Alexa's voice). The Alexa service can take plain text for TTS conversion.



The words the customer says to Alexa to convey what they want to do, or to provide a response to a question Alexa asks. For custom skills, you provide a set of sample utterances mapped to intents as part of your custom interaction model. For smart home skills, the smart home skill API Message Reference provides a predefined set of utterances.


voice user interface (VUI)

A method for people to use voice input to interact with and control computers and devices. For a custom skill, the voice interface consists of a mapping between users' spoken utterances and the intents your cloud-based service can handle. See Interaction Model Schema.


wake word

A command that the customer says to tell Alexa that they want to talk to her. For example, "Alexa, open History Buff." Here, "Alexa" is the wake word. Alexa customers can select from a defined set of wake words: "Alexa", "Amazon", "Echo", and "Computer".