A technology tree is a bundle of timelines; they originate from one path as if a single timeline, but then break into different timelines in much the same way as trees have branches. These branches do not all break off at one point; they break off intermittently. The points at which a timeline branches into two or more are called Points of Divergence. Using a technology tree is effective in cases where the critical technology or change under investigation leads to many different possibilities, some of which may not be mutually compatible. Use of time trees is most effective in scenario analysis.
See Future: Technology Tree for more information and details.