Galaxy surveys are enjoying a renaissance thanks to the advent of multi-object spectrographs on ground-based telescopes. The last 15 years have seen the fruits of this experimental advance, including the 2-degree Field Galaxy Redshift Survey (2dFGRS; Colless M. et al., arXiv:0306581 (2003)) and the Sloan Digital Sky Survey (SDSS; York D.E. et al., Astron. J., 120 (2000) 1579). Most recently, the Baryon Oscillation Spectroscopic Survey (BOSS; Dawson K.S. et al., Astron. J., 145 (2013) 10), part of the SDSS-III project Eisenstein D.J. et al., Astron. J., 142 (2011) 72, has provided the largest volume of the low-redshift Universe ever surveyed with a galaxy density useful for high-precision cosmology. This set of lecture notes looks at some of the physical processes that underpin these measurements, the evolution of measurements themselves, and looks ahead to the next 15 years and the advent of surveys such as the enhanced Baryon Oscillation Spectroscopic Survey (eBOSS), the Dark Energy Spectroscopic Instrument (DESI) and the ESA Euclid satellite mission.