- YAML is just a data serialization language which allows us to store different things. In our case, we use YAML to define a pipeline but YAML can be used for many other things (examples ???)

- to put it very simple, YAML can be used to define key - value pairs. For example name: John. But YAML can also store lists or objects.

- this is exactly what we have done so far, but without going too much into the details of what everything is

- while it may not look like, YAML is actually compatible to another format called JSON

- name: John

age: 23

food:

  - pizza

  - donuts

  - coke

friend:

    name: Joe

    age: 30

    food: null

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