How does this GIS&T Body of Knowledge differ from the original one (published in 2006)?

The content of this digital version has been built directly from the original GIS&T Body of Knowledge, which was published only in paper form. The original 2006 BoK had 329 Topics, organized into 73 Units and 10 Knowledge Areas. Among the 329 Topics there were over 1600 Learning Objectives listed. This entire collection is available here online as the Archived 2nd Quarter 2016 version, and a digital copy (pdf) of the original book can be downloaded too. 

As of its initial launch in August 2016, we began this digital version of the BoK with 306 of the original Topics and their associated Learning Objectives. There are still 10 Knowledge Areas, though some of the original ones no longer exist (such as Geocomputation and Design Aspects). Their Topics have been distributed among the current set of Knowledge Areas, including such new ones as Computing Platforms and Domain Applications. The hierarchical level of Unit will no longer be explicit but will instead groups of Topics can be searched and filtered through keywords.

 The original GIS&T Body of Knowledge was the outcome of a lengthy, multi-year effort by dozens of educators, researchers, and practitioners who aimed to improve GIScience education through the specification and assessment of curricula for a wide range of students constituencies. The initiative, coordinated at times by the Education Committee of UCGIS, a Model Curricula Task Force, and then a team of editors in consultation with a 54-member Advisory Board, eventually produced a comprehensive inventory of the GIS&T knowledge domain. For further information on the history of the first GIS&T Body of Knowledge, please read its Section IV: How Was the Body of Knowledge Developed (pdf). 
As stewards of the GIS&T Body of Knowledge, it is the intent of UCGIS to maintain its content in a manner that is open and accessible to everyone in the global GIS&T community. The first version of the BoK served this community well for over a decade, but a revision and updating was overdue. Substantial numbers of new Topics will be added in the coming months, and in its new form, individual authors will be recognized for their peer-reviewed scholarly contributions. Each Topic will have its own DOI and static, permanent URL. The digital form facilitates searching, browsing, and regular updating. The most current content will be shared as soon as possible, and earlier versions of content will be available online through the Archives.