Yes.
There is a huge difference between heavy metal and death metal. However, to somebody that doesn't listen to metal, it all sounds the same, and is widely regarded as 'noise.'
The difference between heavy metal and death metal is largely 1) the vocals, and 2) speed of the music. Most people are put off by the vocals, which I can understand. It's abrasive, and certainly not for everybody. On the other hand, the music behind the vocals is quite often extremely technical, well written, and very difficult to play. That's what death metal has evolved into today. How fast can we play, and how much can we challenge ourselves with odd time changes, yet still make a cohesive song.
For somebody that hasn't listened to much/any death metal, I would recommend some Arch Enemy. Some of the best guitar solos and leads you'll hear in metal. They're pretty heavy, and labeled as 'melodic death metal,' though they're straying from death metal more and more with each album. Still though, awesome guitars.
What kind of stuff are you into now? Just Pantera?