For example, the [String Length] attribute used on the First Name property specifies the maximum length for First Name to be 50 and Minimum Length to be 3.
The [String Length] attribute is used to specify the maximum length and optionally the minimum length for a property value.However, in this case our model class is an Entity Framework class.Since the data model class is automatically created for you by the Visual Studio designer it is not recommended to modify the same class file.The [Display Name] attribute is used to specify a friendly name for the property under consideration.
This friendly name is used by HTML helpers such as Html. If you don't use the [Display Name] attribute a property name will be used for display purpose.
The User Profile Metadata class contains property definitions for First Name, Last Name, Email, Bio, Age, Blog Url and Phone.