This course gives the fundamental concepts of algebraic numbers.

Principal ideal domain and unique factorization domains, commutative fields, residue classes, quadratic residues,algebraic ıntegers, ıntegral basis, discriminant, the decomposition of ıdeals, the norm and classes of ıdeals, units and estimations fort he discriminant, ramification, discriminant and different, the ramification of prime ıdeals in galois extension, the fundamental theorem of abelian extensions, miscellaneous numerical examples.