[musictlk] A question about the mandolin

[Joshua Lester]

http://www.oldfashionedrevivals.com
I post this Website on here, because it says that Freddy Clark, and
his children are gifted musicians, that play a variety of instruments,
including the mandolin, and the mandola.
What's the difference between those two instruments?
I went to Youtube, and both instruments, sound the same.
Thanks, Joshua