Chemotherapy can be given in quite a few ways:
Orally (by mouth, in pill form)
Intravenously (IV, through a vein, either as a short infusion or continuously for one or more days)
As an injection or needle
Directly into a body cavity (i.e.: the bladder, abdominal cavity)
Intra-arterially (in special cases, such as limb perfusion treatment for melanoma)