In graphql what is difference between a `type query` and `extend type query`? ❤️ {UPDATED 2023}

In graphql what is difference between a type query and extend type query?

Ex: difference between

type Query {
    product(id: String!): Product
}

and

extend type Query {
    DeviceDetail(devId: String!): DeviceDetail
}

Will appreciate if you could add an example for your explanation.

You can only declare a type once, but you can extend it multiple times

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@Bergi – +1. will appreciate if you can add an answer with an example or provide any doc/article reference.

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@Bergi – you mean or refer to the schema file. In schema file You can only declare a type once, but you can extend it multiple times. Is this what you mean.

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Where else if not in a schema file would you find this code?

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