Multiline
Magento\Customer\Model\Attribute\Data\Multiline
What it does
This class handles customer attributes that contain multiple lines of text data, such as street addresses.
It extends Magento's base EAV Multiline data model to provide customer-specific handling for multi-line attribute values during validation, input/output operations, and data processing.
Developers use this when working with customer attributes that require multiple text input lines.