If encryption is enabled on a share, only encrypted client connections can access the share. You can enable or disable encryption on a CIFS share while creating a new share or by selecting an individual share. For more information on managing encryption, see How to manage encryption on a CIFS share?.
Encryption can be enabled or disabled at the share level whereas if encryption is applied at the global level then no need to apply it at the share level. You can enable encryption on individual shares if encryption is disabled at the global level.