The building blocks of an App are what we refer to as
Elements are two-way interactive components such as Polls, Predictions or Trivia questions which have a range of configuration fields and typically have two-way behaviour that allows them to count up votes or responses from users.
Note that every App has a different set of Elements; the developer of the App decides which Elements to use and which to hide. There is no such thing as a 'standard' set of Elements.
An example of Elements available in an Experience
An example of Element settings