This document provides an overview of the Human Capital Index, which measures human capital development around the world. The index covers four pillars: health and wellness, education, workforce and employment, and an enabling environment. It uses 51 indicators to measure these pillars, capturing factors like education levels, health, employment rates, and the context in which human capital operates. The document explains the methodology and indicators used in the index and aims to provide a framework for benchmarking and discussing human capital across countries. It also introduces the country profiles included in Part 2 which provide more detailed analysis of human capital for each country.