For easy access to a network resource such as sharing folders, sharing printers, etc, so as not to fill the password over and over again when we will access it again, Windows provides save password (usually under the username and password fields have option to unchecked/diceklis so that the password is stored, so we do not need to fill in your username and password again when going to access it again).
When the password for the resource-sharing that has changed on the computer then certainly we should also changed the password, otherwise, would not be able to access and there will be a notification error.