There are lots of different kinds of seed beads.
So many different kinds of beads that I can't keep track of all of them. To me they divide down into 2 categories, Japanese Beads and Czech Beads.
So the beads here on my site are marked "J" for Japanese, and "C" of Czech Beads.
If you buy beads in your local bead store and are trying to match the color by a number.
Then you want to look for the numbers on the Japanese Beads.
Now lots of people buy Japanese Beads because they are more uniform and easier to locate the same color.
I myself, like the Czech Beads. Yes they can be different sizes, but this to me can be a good thing as I do a lot of 3 dimensional beadwork. They also add a lot more variety to the colors that can go into a piece of beadwork. The colors in Czech Beads also last longer, unless they say DY after the number, because this means they are dyed. All of the Japanese Beads that have color are dyed. The color in the Czech Beads is in the glass.

If there is a question as to which is better, the answer is in what you are making at the time.
Each type of bead has it's own place.

We all have our preferences in beads too.
I like Black the very best!!
I like mostly silver lined beads, then pearly looking beads, and the color lined beads are becoming more and more interesting to me all the time.