what is model schema document in mongo db

package main

import (
    "context"
    "fmt"
    "log"
    "time"

    "go.mongodb.org/mongo-driver/bson"
    "go.mongodb.org/mongo-driver/mongo"
    "go.mongodb.org/mongo-driver/mongo/options"
)

type Person struct {
    ID        primitive.ObjectID `bson:"_id,omitempty"`
    Name      string             `bson:"name,omitempty"`
    Age       int                `bson:"age,omitempty"`
    Email     string             `bson:"email,omitempty"`
    CreatedAt time.Time          `bson:"createdAt,omitempty"`
}

func main() {
    client, err := mongo.Connect(context.TODO(), options.Client().ApplyURI("mongodb://localhost:27017"))
    if err != nil {
        log.Fatal(err)
    }

    err = client.Ping(context.TODO(), nil)
    if err != nil {
        log.Fatal(err)
    }

    fmt.Println("Connected to MongoDB!")

    collection := client.Database("your_database").Collection("persons")

    // Create a new person
    person := Person{
        Name:      "John Doe",
        Age:       30,
        Email:     "[email protected]",
        CreatedAt: time.Now(),
    }

    // Insert the person document into the collection
    insertResult, err := collection.InsertOne(context.TODO(), person)
    if err != nil {
        log.Fatal(err)
    }

    fmt.Println("Inserted document with ID:", insertResult.InsertedID)

    // Query the person document
    var result Person
    filter := bson.D{{"name", "John Doe"}}
    err = collection.FindOne(context.TODO(), filter).Decode(&result)
    if err != nil {
        log.Fatal(err)
    }

    fmt.Printf("Found document: %+v\n", result)
}