The centimetre is a unit of length and is a multiple of the metre; an SI derived unit. It has the symbol cm.
A centimetre is equal to 0.01m. It is also ≈ 0.3937in.
Centimetres are used in maps to scale up conversions to real world measurements.
The angstrom (or ångström) is a unit of length and is a non-SI but metric accepted unit with the symbol Å.
It is equal in length to one ten-billionth of a metre or 0.1 nanometres (0.1nm).
It is approximately the size of an atom and is mostly used to measure very small distances for example wavelengths of light.