AkaiYuki thanks for making it clear. but just one more question shonen ai is like clamp series right? and yaoi is like Gravitation? am i right? i'm not sure if i get it correctly.
Weeellllll, actually... Not quite.. You're close, though! This is kind of hard to explain...
As far as CLAMP goes, some people would say their shounen-ai content is only "hinted" so some people may and some people may not call it "shounen-ai" series... They may just call it a "slash" series, which means it's a regular series that can easily be perceived or changed around to be shounen-ai... (Though anyone who doesn't think Tokyo Babylon is shounen-ai is kind of crazy in my opionion...)
But Gravitation doesn't quite qualify as "yaoi".. Unless you're talking about the Gravitation Remixes, which DEFINITELY qualify as yaoi... XD Hmmm.... I guess to make it easier, shounen-ai is more limited to kissing while yaoi is... ummm... not so limited?? XD Heh heh, know what I mean?
Not to make this more confusing or anything, but really the term "shounen-ai" is hardly used anymore (at least in Japan) and there are tons and tons of words for both shounen-ai AND yaoi, but in America, the general fan consensus says "shounen-ai" for sweet things and "yaoi" for graphic things... ((But of course, to make it confusing, some say "BL" for shounen-ai, which stands for "boys love" just because "shounen-ai" is an obsolete term in Japan.. Which I find to be a stupid excuse as they're basically saying the same obsolete term in another language... Morons...))
These terms aren't 100%, but most people will know what you're talking about if you say any of the ones I just used...