What are Mongoose schema types and validators?

const schema = new mongoose.Schema({
  // String
  name: String,

  // Number
  age: Number,

  // Boolean
  isActive: Boolean,

  // Date
  createdAt: Date,

  // ObjectId reference
  author: { type: mongoose.Schema.Types.ObjectId, ref: 'User' },

  // Array of strings
  tags: [String],

  // Array of objects
  comments: [{ text: String, date: Date }],

  // Nested object
  address: {
    street: String,
    city: String,
    zip: String
  },

  // Mixed (any type)
  metadata: mongoose.Schema.Types.Mixed
});

const userSchema = new mongoose.Schema({
  email: {
    type: String,
    required: [true, 'Email is required'],
    unique: true,
    lowercase: true,
    trim: true,
    match: [/^\S+@\S+\.\S+$/, 'Invalid email']
  },
  age: {
    type: Number,
    min: [0, 'Age cannot be negative'],
    max: [120, 'Age too high']
  },
  role: {
    type: String,
    enum: ['user', 'admin', 'moderator'],
    default: 'user'
  },
  username: {
    type: String,
    minlength: 3,
    maxlength: 30
  }
});

const schema = new mongoose.Schema({
  phone: {
    type: String,
    validate: {
      validator: function(v) {
        return /\d{10}/.test(v);
      },
      message: 'Invalid phone number'
    }
  }
});