If an employee attempts to edit the description field after submitting an opportunity for approval, they will be presented with a 'Record Lock' notification. This means that the record is locked for editing while it is in the approval process and only users with the "Modify All" permission or users above them in the role hierarchy can edit it. [Source]

The functionality that should be used to set up packages is namespace. A namespace is a unique identifier that distinguishes one package from another and prevents naming conflicts with other packages or customizations.
A namespace also allows developers to expose their code or components for use by other developers through APIs or web services. A description is not a functionality that should be used to set up packages, but a text field that provides information about the package contents or purpose. A description does not prevent conflicts with other packages or customizations. Allow sharing is not a functionality that should be used to set up packages, but a setting that controls whether users can share records owned by other users within their role hierarchy. Allow sharing does not prevent conflicts with other packages or customizations. Help setting is not a functionality that should be used to set up packages, but a setting that determines whether users can access help documentation for standard Salesforce features or custom features within a package. Help setting does not prevent conflicts with other packages or customizations.

Workflows that cause each other to fire back and forth recursively can result in workflow limits errors. For example, if workflow A updates a field that triggers workflow B, and workflow B updates a field that triggers workflow A, this can create an infinite loop of workflows that exceed the maximum number of workflow time triggers per hour.

The lookup relationship will need to be converted to a master-detail relationship before a roll-up summary field can be created. This is correct because roll-up summary fields are only available on the master object in a master-detail relationship, and a lookup relationship does not establish a parent-child hierarchy between the objects

Before replacing workflow rules and Apex triggers with Process Builders, the app builder should consider avoiding generating infinite loops and combining actions when possible. Infinite loops can occur when a process updates a record that causes another process to run on the same record, and so on. Combining actions can reduce the number of processes and improve performance and maintainability