Because ultrashort laser pulses can act as incredibly fast probes, physicists, chemists and biologists now routinely use lasers with durations as low as ~5 femtoseconds to study and control the dynamics of atoms, molecules, and electrons. Ultrashort laser pulses are beginning to be used for multiphoton microscopy, micromachining and as a potential atomic clocks. For any of these uses, and for developing ultrashort pulse lasers, it is vital to be able to accurately measure the temporal and spectral intensity and phase of ultrashort pulses. This course presents the terminology, properties and methods for measurement.