Males with long tails vs. males with short?

[bimmerboy]

I've seen alot of male guppies with the long flowing tail fin like show guppies... and some that have a "normal" tail. Is there a name difference? Are these not as desireable?

 

[Tempestuousfury]

They might have been wild as opposed to tank-bred.

Also, there are different tail and fin varieties, such as lyretail, sailfin, hifin, etc. These are characteristics that are specially bred for show and display. Fish that have these fins look good in a tank, but there's nothing wrong with getting either. It's just that if you breed one or the other, the chances of getting offspring that have a certain characteristic is greater with certain parents.