In 1996, the first single-molecule Förster Resonance Energy Transfer (smFRET) experiments were published, demonstrating that the possibility of measuring FRET efficiencies on individual molecules and opening a new direction for the biophysical sciences. With smFRET studies, heterogeneities can be observed directly and dynamics can be measured without synchronization. Since FRET is sensitive to distances, combined studies at the single-molecule and ensemble levels have emerged as excellent tools for measuring structural dynamics and mapping the conformational landscape and functional heterogeneities of biomolecules under ambient conditions. In honor of this historic occasion, this conference will act as a forum to discuss the current advances and challenges for FRET experiments and theory.