In Quantum mechanics, we frequently deal with eigen value equations. When we speak of eigen value equations, we come across terms like eigen values,eigen vectors,eigen functions etc. When an operator is operated on certain quantities we get the same quantity multiplied by a constant. These quantities are interchangeably referred as eigen vectors and eigen functions. But do they mean the same? Is it something like, we call it as eigenfunctions in Schrodinger formalism and eigenvectors or eigenkets in Heisenberg formalism or is there a ma thematical difference between the 2?