The phrase "extensive selections" refers to a large number or variety of choices available. It can be used in various contexts, such as referring to a wide range of products, services, or options that someone has to choose from. For example, if you are looking for a new car and go to a dealership, they may have an extensive selection of vehicles to offer. Similarly, if you are planning a vacation, there may be extensive selections available in terms of destinations, accommodations, activities, etc., that you can choose from. The phrase highlights the fact that there is plenty to choose from and that one has many options to consider before making a decision.