ends with / does not ends with will allow you to use individual mapping methods for individual products or product groups.
You can assign some values to products depending on what the value ends with.
You can use this option to set the value Store Name for the brand attribute if the source's title attribute ends with Store Name. If it does not ends with Store Name, Generic value will be set.
It is always recommended to have a Fallback rule for products that are not matched by the condition, just to make sure that there are no empty values in your output feed.