Sync is a process that synchronizes the data between the model and the destination. Sync consists of reference to a connection, reference to model that is being synchronized and an optional enrichment configuration. It’s defined in a syncs folder in the project directory in a .yaml or .yml file. 
model: all-users
destination: facebook
options:
  ...
  ...
enrichments:
  ...
  ...
model references the model by id. The id of the model equals the name of the model file without the .yaml extension, unless the parameter id is explicitly set in the model file. destination references the connection by id. The id of the connection equals the name of the connection file without the .yaml extension, the parameter id is explicitly set in the destination file. options set the configuration for connection. They are specific to connection

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Enrichment