The ITER project has an overall programmatic objective `to demonstrate the scientific and technological feasibility of fusion energy for peaceful purposes'. The ITER tokamak design is the embodiment of the finding, endorsed by all the parties to the project, that `the full non-linear interplay between alpha-particle heating, confinement barriers and pressure and profile control, and their compatibility with a divertor can be addressed only in an integrated step'. This step involves not only the study of fusion burning plasma physics but also the demonstration of key items of fusion reactor technology.This paper introduces: magnetic fusion plasma (section 1), the physics goals of ITER (section 2) and the burning plasma physics which will be studied (section 3), examines the present ITER design and how it meets the plasma performance requirements in terms of extended burn at specific fusion power amplification (section 4), describes plasma measurements for ITER and some of the issues involved in their implementation (section 5), indicates how ITER provides a focus for international research into tokamak plasma physics (section 6), and presents a brief report on the status of the ITER Project (section 7). To conclude, this paper presents some final remarks (section 8).