A smartphone is a cell phone that allows you to make calls like all phones, but has additional features such as email and internet. Smartphones usually also have applications like games, PDA viewer, or Microsoft Office applications.
Smartphone is like something more than a normal phone wherein you can do more things than just calls and messages. There is no standard definition, however any phone that has more features like emails and internet access and PC like functions can be called a smartphone.
A smartphone is a phone that has the capability to do more than a regular mobile phone. You can add applications that will let you many things a computer can.
A mobile phone offering particular services like e-mail, web access, calender and to-do lists. Sometimes offers also office functions, at least to read MS Word, Excel and PDF files