Hi endah,
Sorry for just replying now, although it is a bit more complex i will explain it briefly:
The TOSEC project appeared +- 14 years ago as a rom cataloging project with the goal of helping to identify / sort these files and name it according to a convention (TNC - Tosec Naming Convention) - so, it started as a renaming project.
AFAIK, somewhere between 2006 or 2007 (my guess) a dumping project started named toseciso. The goal was to dump only original optical media and catalog it (in part to avoid what happened previously with other media types - lots of formats and bad dumps). The process of dumping isos has always been an open debate with other projects claiming "the right method" and so on.
During the last years the whole project slowed down with the disappearing of many key members. Nowadays, the TOSEC renaming project continues to work at this location. The old dumping project site went offline (toseciso.org). Meanwhile a few members of it were working on a new dumping tool / method (aka trurip) and lately they started releasing dumps. Although there is not many documentation about the method, it is claimed to be "the correct one" and members started redumping collections with it (except Maddog, the DC dumper). They also started using the tosec-iso.org domain.
That's it! I tried to explain it the better, non bias i could. Basically the renaming project is hosted here, the old dumping project is dead and some of their members with are now dumping / redumping with the new tool. They also dat their isos but i'm not sure the TNC convention is being followed. Here in the downloads section our last release still contains the toseciso dats with the older method.
As for the TOSEC 2.0, that notation started at the end of 2003 with the release of the renewed site and system to generate that and all that at the older site (tosec.info), you can still read that explanation in the site FAQ (a copy of that is available in wayback machine / internet archive).