A skew hermitian matrix is equal to the negation of it's complex conjugate transpose A=-A' .The entries on the diagonal of a skew hermitian are always pure imaginary or zero.
A hermitian matrix is equal to it's own conjugate transpose that is the element in the i-th row and j-th column is equal to the complex conjugate of the element in the j-th row and i-th column for all i,j.