The "Presets" Tab purpose is helping you start configuring your audience faster. You first start in this section finding your audience. You should find something similar to your intended audience. If you don't find it, you should select something similar and then go into the "Define Advanced Audience" section and tweak it further.
For example, if I am looking to create an audience setting to match the visitors in France, if I go to the "Presets" tab, and then select the "Language and Geo" section, and then select the "Country" section, I will not find "France" as a choice. So, I could select the "USA" choice, and then click on "Define Advanced Audience" and select the drop down where the "USA" is selected, and change it for the "France" option.
This helps me create complex audience settings, without having to create them from scratch in the "Define Advance Audience" section.
1) Traffic Presets
Traffic presets, allow you to utilize data related to the traffic data of the visitor.
a) Traffic Sources Presets
They allow you to use the traffic origin of the visitor for your audience.
b) Visitor Type Presets
"Visitor Type Presets" allow you to create an audience setting based on whether a visitor is a "New Visitor", or a "Returning Visitor" to your site.
2) Social Presets
These allow you to include or exclude traffic that originates from social networks. This setting relies on the data provided by the utm_source tag of your traffic.
3) Language and Geographic Presets
These allows you to create an audience to include or exclude traffic that originates from a specific geographical area. The geographical area of where your visitor comes from is taken from an IP location database.
a) Continent, Country, USA States
If you don't find your desired location, select one similar to it, and then go into the "Define Advanced Audience" and select the one you would like from the drop down.
This setting comes from the preferred language selected in the visitor browser.