Ibiza - Eivissa in Catalan -, is one of the most visited islands in the group of the Balearic Islands in Spain, and famous due to its amazing nightlife. Therefore it attracts the highest amount of young people as well, although the island also offers a wide range of options for those not interested in the club scene.
There are many other activities suitable for visitors of all ages and preferences.
From June till the end of October, in tourist season, Ibiza night life, as well as all other attractions in the island, is at its best but there are lots of bars where you can have a drink and talk, without loud music.
But when you visit the island between October and May and you'll find a very different, much more peaceful island - only one club and a few funky bars remain open through the winter months.  
The Ibiza nightlife districts, aside from the clubs, are mainly in Puerto de Ibiza = Port of Ibiza, known as 'La Marina' where you find many terraces and restaurants and which is full of the liveliest bars as is San Antonio's West End.