Confusion with DVDs

I just bought a new eMac Superdrive and I am trying for first time to copy some of my family movies into a DVD.

As per shop assistant suggestion I bought a couple of DVD-RW so in case I want to erase the movies or data I can easily reuse the disc. On the disk is written: speed up to 2x 120 min.

I am not able to see the movies in my Mac and DVD player. Why ?

In the market there are different types of discs, which are suitable for the eMac ?

Why there are DVD-RW discs which the Mac apparently cannot read.

But I thought my eMac could use any typ of DVD.

The strabge thing is that I copied all my data into a DVD-RW and that can be opened without problems.

Could you please clarify all these points ?

Thanks

Ferro

We need more information:

Like how you created the DVD?
What application did you use?

Also on a side most DVD player, except for the newer ones will not be able to read a DVD-RW.

Also for the heck of it, what type did you buy? Some have more problems then others. *I'm wont name names, but *cough* Tdk *cough**

Cheers!
Justin