Generally, smartphone implies qwerty keyboards or touchscreen displaying, grantig an interactive interaction of the user with his gadget
A smartphone will always include apps, to facilitate your work or provide you entertainment
In addition, smartphones include better cameras, graphics and sound quality
Each manufacturer aims to create an unique model, to be considered the best on a crowded market. For example, Htc included Beats Audio feature, while Samsung created a suite of apps to fulfil customers' recurrent needs