Gives 100% of the credit for a conversion to the last click, if the last click is on a paid search ad. If the last click is from a display ad, the conversion is not recorded. If the last click is from natural search, the conversion is not recorded unless you subscribe to Search Ads 360 Natural Search and choose the appropriate attribution option.
The last-click attribution model is used by default to distribute credit in Floodlight activity or Google Analytics activity columns, and bid strategies.