A quick guide to understanding new Windows Mobile Devices - taken from
"Pocket PC" is now called "Windows Mobile Classic" for touch screen devices without a phone built in (such as the iPAQ 111) and "Windows Mobile Professional" if its a touch screen with a phone (HTC Touch, Xperia, Palm 750)
If its a Windows phone without a touchscreen its called "Windows Mobile Standard" - previously known as Windows Mobile Smartphone (Samsung Blackjack, MotoQ)
Now - for compatibility - software created for Pocket PCs usally works on newer Windows Mobile touch screen devices "Professional/Standard". Especially if it was created for Pocket PC 2003 SE (which introduced VGA, square, and landscape screens).
However - if you buy a Windows Mobile phone with a high-resolution screen (VGA / XVGA), a square screen or one that primarily works in landscape orientation (the screen is wider than it is tall) the software may not work.
Its a little tougher with non-touch screen devices. The original Windows Mobile Smartphone has a low resolution screen - 172x220 so most old software only supports this resolution. New Windows Mobile Standard phones are almost always 320x240 or 240x320 so I would make sure that Windows Mobile Standard compatibility is specifically mentioned before purchasing any software.