An Invocation Name is a name that the user of a skill will speak and Alexa will use it to summon or identify your skill from its list of enabled/available skills. An example of a sample skill invocation is shown in the following screenshot:
Please note that in the preceding example, we are using a one-word invocation name, which normally isn't allowed by Alexa unless the invocation name is unique to your brand/IP. In the case of Spotify, this is true. Amazon has defined various rules regarding invocation names and these can be found on the Amazon Developer Portal.