That is, each point in the medium oscillates with fixed amplitude. There are locations at which the medium does not move at all, called nodes , and locations at which the medium oscillated with maximum amplitude, called antinodes . In a guitar string, standing waves must obey the constraint that there must be nodes at both ends of the string, since the string is fixed at both ends. The distance between adjacent nodes of a standing wave is exactly . Larger values of n have larger numbers of nodes.
Frequency is related to wavelength via the speed of the wave.