Validation rule is a tool that can be used to enforce data quality and business logic by preventing users from saving records that do not meet certain criteria. In this case, a validation rule can be created on the Lead object to display an error message if the Lead Status field is marked as qualified and the Budget field is blank. Reference: https://help.salesforce.com/s/articleView?id=sf.fields_about_validation_rules.htm&type=5

Master-detail lookup is a type of relationship field that can be used to create a relationship between Account and Shoe and prevent orphaned Shoe records. Master-detail lookup establishes a parent-child relationship between two objects, where the parent record controls certain behaviors of the child record, such as security, ownership, and deletion. If the parent record is deleted, all the child records are deleted as well. Reference: https://help.salesforce.com/s/articleView?id=sf.relationships_considerations.htm&type=5

Record types and sales processes allow you to have different page layouts, fields, required fields, and picklist values for different types of opportunities.

A master-detail relationship is a parent-child relationship in which the master object controls certain behaviors of the detail object. The master object can be a standard or custom object, but not all standard objects support being a master. Roll-up summaries are fields that calculate the sum, count, min, or max of child records. The owner field on the detail records is not available and is automatically set to the owner of the master record.

Component visibility allows you to restrict the visibility of a related list based on a permission set.