Bulk, 2x or 4x or 1-4x? the difference?

Can someone tell me what the difference is when buying discs. some are marked bulk (nothing listed) some 2x some 4x, some 1-4x. What do I want? Does this mean the maximum burn speed?
Thanks in advance. Bob

Bulk means they will have no labeling on the disc, just plain silver.
1-4x means they are 4x rated, 2x means they burn at 2x only.
Some drives support 1x burning, others do not and will burn only at 2x and 4x. Other drives will burn at 1x, 2x or 4x.

Mr. Moderator,
Thanks for your help today. I have a NEC 2500 that burns up to 8X. What discs should I get.??? This is getting confusing. Dont -rs only burn at 4x max anyways? Thanks

Get TY, +R or -R, or Maxell -R, all of which are made in Japan.
Any +R will do well in the NEC, TY and Mitsubishi -R will burn at 8x BTW.

Mr Moderator. Thanks I will take your advice. Last question, do I want the 4x or other? and do I want the general purpose or reauthoring? Im gonna get the the TY +r

P.S can you recommend a good internet site to buy them. There are so many its boggling.