Final answer:
In the "last-click" attribution model, GA attributes all conversion credit to the last source that referred the user before the conversion event occurs.
Step-by-step explanation:
In the "last-click" attribution model used in G Analytics (GA), all the conversion credit is attributed to the last source through which the user arrived at the website before converting. This model assumes that the final click is the most critical up until the point of conversion, regardless of the user's interaction with other marketing touchpoints along their journey. In practice, if a user clicked on a banner ad, then a FB post, and finally searched for the website via a search engine and converted, 100% of the conversion credit would go to the search engine.