external hard drive desktop vs portable

I'm looking to get a external Hard drive. I'm not sure what to do Desk top or portable I'm looking for one because I only have one laptop and I use it for work but I also use it for club stuff and I would like to be able to place all the club pictures documents and stuff on the extrenal and keep just the work stuff on the laptop. Now one of my issues is that I would like to be able to put club programs on it to but I will need to be able to use them on the laptop from the drive. For example we make maps for the club so I would like to place the mapping program on the extrenal drive along with the maps and more.

Can any one tell me what I can do if any thing.

 

For general information,a desktop external 3.5" type drive
is bigger and requires the use of external AC power.
A portable 2.5" external drive is smaller and uses a second
USB port to power the drive.
It doesn't need AC power.
Drive letter assignments can change when plugging drives
into different USB ports.
That can cause programs on the drive to malfunction.
It would be better to install the programs on the laptop
and keep the files they generate on the external as you
can usually change the location in the program preferences
as needed.
If it is a standalone program that runs without having to be
installed,then it could be put on the drive.
There are a lot of portable applications out there made
specifically for portable drives and flash drives.