[gmx-users] definition of "eigenvector" in gromacs

[Brett]

Dear All,
 
Recently I have read a gromacs related article which contain a sentence "Trajectories pojected on the first two eigenvectors". Will you please tell me the meaning of "eigenvector" and "Trajectories pojected on the first two eigenvectors"? Will you please also explain it to me using common-used words simple as desk, meal, earth, etc?
 
Brett