what is the better eig function or pcacov and what the different between them

Hi ,,,,i want to extract the eigenvector on my dataset.. i know there are any function like (pcacov and eig)..i read is both functions get us the eig vectors my question: can i used both functions or one of them to finding eigenvectors??? i found code :

 [n m] = size(A);
 AMean = mean(A);
  AStd = std(A);
 % disp(AMean);
  B = (A - repmat(AMean,[n 1])) ./ repmat(AStd,[n 1]);
  B = zscore(A);

can i used instead of pcacov??? plz help me