PDA cell phone! Provide its advantage and disadvantage.

Some people say that PDAs and smartphones are one and the same thing with the only difference in their name but I don't agree with such people because as far as i've learnt about these devices, PDA (Personal Digital Assistant) cell phone is a handheld computer that can also be used as a mobile phone where as smartphones are converged devices that combines the functionalities of a PDA and a cell phone. PDAs are normally cheaper than smartphones over the life of the device. Initially, some smartphone costs less than a pda cell phone but due to wireless carrier subsidies, you’ll often end up paying more for a smartphone over one or two years than you would with a PDA because of ongoing costs. A pda cell phone can definitely prove to be a small replacement of your laptop. Advantages of using a laptop are that it has been quite useful in the Traumatic Brain Injury/Posttraumatic Stress. They are advantageous in various other ways such as view journal articles, clinical photos and movies, write and rehearse PowerPoint presentations, collect audit data in clinics, compile logbooks in clinics/theatre,etc. Some of the disadvantages of PDAs that i'm aware of are that there battery life is limited and there is no standard connection to charge them up.