Cameras with more dynamic range allow you to take photos with dramatic differences in highlight and shadow areas while retaining detail in both.
Think of a brilliant sunset on a rocky beach: Bright sunset in the background, with dark rocks in the foreground. High dynamic range means more of the extremes will be faithfully reproduced.
Dynamic range test data courtesy of DxO Mark.PEN-F test data on DxO Mark SL1 test data on DxO Mark
Extremely compact and lightweight for a DSLR; Delivers good image quality that's virtually identical to the Canon T4i/T5i; Accurate and relatively fast autofocus with improved Live View and Movie Hybrid CMOS II AF; Full 1080p HD movie recording; Better-than average kit lens (EF-S 18-55mm f/3.5-5.6 IS STM).
Still not as compact as most mirrorless cameras; Slightly worse than average dynamic range and high ISO performance; Poor battery life.
Highest resolution Olympus 4/3" camera yet; Excellent image quality for its class; Very good dynamic range; Fast autofocus; Fast burst speeds; Lots of fun creative filter options; Built-in EVF, Wi-Fi.
Expensive; No weather sealing; Mediocre battery life; No 4K video; No mic or headphone jacks.