The point is a unit of length in the field of typography and uses the symbol pt.
It is the smallest unit in the world of typography. There are 12 points in a pica.
In physical printing methods / press systems, the point size is the height of the metal press body on which the font's letters are made. When applied to the digital type space, letters are designed around a theoretical size, an em square which is scaled to the relative point size (when specified of course!).
The picometre is a unit of length and is a multiple of the SI unit metre. It uses the symbol pm.
It represents one trillionth of a metre, or one hundredth of an Ångström.
Because the picometre is so small, its use is restricted almost entirely to chemistry, quantum physics and particle physics. Atoms are typically 62 pm and 520 pm.
LISA (Laser Interferometer Space Antenna) is a probe planned for launch in 2034 to detect gravitational waves in space. Its measures these displacements with an accuracy of up to 20 pm over a distance of 2,500,000,000 m.