Ultrafast spectroscopy is a technique used to study the rapid processes that occur in materials and molecules on extremely short timescales, typically in the range of femtoseconds (10^-15 seconds) to picoseconds (10^-12 seconds). This method allows scientists to observe how electrons and atoms move and interact during chemical reactions, providing insights into fundamental physical and chemical phenomena. By using short pulses of light, ultrafast spectroscopy captures snapshots of these fast events, enabling researchers to create detailed time-resolved images of molecular dynamics. This technique is essential in fields such as chemistry, physics, and materials science, helping to advance our understanding of processes like photosynthesis and energy transfer.