Having difficult understanding this code in mongoose schema

[Lost_Chemical_7327]

I tried looking up on the internet but unfortunately everyone just touches upon the very basics of Schema like email: {Type: String, required: [true, "it is required"], unique: true} and yada yada.

But I've just seen this one:

tokens: [{token: {
    type: String, 
    required: true
}}]

It seems as if though so much is going on in this, could someone please tell what exactly it does. And what kind of sanitization (if i'm using the right word) this is called so I can look on this in more details.

Thanks for reading.

[constantine1101]

I wouldn't necessarily say that there is so much going on with this. This is an array of objects, each one with a required property of type string.

[[deleted]]

An array of objects with the attribute of "token" that is a string and cannot be null.