Yep one {...} is used to define a single object, while the other [...] is used to define a sequence of either objects, values or lists …
objects are defined as such {key:object or list or value , ...}
list ares nothing more than a sequence of either objects or lists or values, [objects or list or values, ... ]…
[{'value':1}, {'values':[1,2,3,3, {'a':'a', 'b':'b'}]}, 2, 3, 4]