  From Mercury's perihelion precession (open question from 1845 to 1915) to
Gravity Probe-B satellite (first proposal in 1959, launch in 2004), General
Relativity had to deal with precession phenomena. Perihelion advancement
precession (Einstein), geodetic (de Sitter), gravitomagnetic (Lense-Thirring)
and spin-spin (Pugh-Schiff) precession are compared with all Newtonian terms in
cases of weak and strong gravitational fields. Qualitative models and order of
magnitude estimates from classical papers are presented.
