There are certain things in user interfaces that are eternal. Whatever the trend is — skeuomorphic, minimal, flat — designers will adapt to the current situation. One of the integral bricks of any good design is icons.
As a clear graphical representation, an icon naturally bridges the gap between the web application and user. You do not need words — an icon can say everything for you. Whether it is just a minimal line style pictogram like Icons from Swifticons or lavish and bright pictograms like one from Material Icons Bundle by Iconshock most likely, your users will receive the proper message.