[] means an array of object (a list)
and {} means it will be an object.
Example:
{
"ID":"test",
"sports": [
"volley-ball",
"badminton"
]
}
To get the ID, you can do: myjsonobject.ID (here you will get "test")
And for sports: myjsonobject.sports[0] (here you will get "volley-ball")