The Western Hemisphere refers to the western part of the world, which can be defined in different ways.
In geography, the Western Hemisphere refers to the half of the world that lies to the west of the Greenwich Meridian and east of the International Date Line. This includes the westernmost part of Europe, part of Africa, and the whole of North America and South America.
In political commentary, the Western Hemisphere (or 'the Western World' or simply 'The West') is a subjective term referring to those developed countries that historically had a strong Western European influence. In this definition, Western Europe and North America are included as a minimum. Depending on the context, South America, South Africa, Australia, New Zealand, Eastern Europe, and other places might also be included.