Explore the current state of Quark Transverse Momentum Dependent Parton Distribution Functions (TMDs) in this 51-minute lecture by Alessandro Bacchetta. Delivered as part of the International School and Workshop on Probing Hadron Structure at the Electron-Ion Collider, gain insights into the fundamental building blocks of protons and neutrons. Learn about the upcoming electron-ion collider (EIC) at Brookhaven National Lab and its potential to revolutionize our understanding of nucleon structure, mass generation in visible matter, and the role of quarks and gluons in proton spin. Discover how the EIC's high luminosity and wide kinematical coverage will provide unprecedented access to new information about hadron structure.