This document provides an overview of world expos and their history from the first Great Exhibition in 1851 to predictions for future expos. It discusses how expos started as markets and fairs to showcase innovations and technologies and evolved into large global events. Key details include attendance numbers and costs for major expos, the themes expos have focused on, how countries participate through national pavilions, and predictions that expos will continue facilitating the sharing of ideas to welcome future technologies and improvements.