Processor and RAM internal distances determine the size of internal components and the number of items.
2011 common distance was 32 nanometers (nm).
Next goal is 22 nm.
Placing items closer together means more capacity per chip and it can reduce heat and power consumption, and improve performance.
Comparisons
A nanometer is one-billionth of a meter.
Paper thickness (20 pound): 0.004 inches = 0.1 millimeter = 100 micrometers = 100,000 nm.
A green laser pointer has a wavelength of 532 nm.
X-ray wavelength is from 0.01 to 10 nm.