World is a common name for the sum of human civilization, specifically human experience, history, or the human condition in general, worldwide, i.e. anywhere on Earth.
In a philosophical context it may refer to the Universe, everything that constitutes reality. In a theological context, world usually refers to the material or the profane sphere, as opposed to the celestial, spiritual, transcendent or sacred. The "end of the world" refers to scenarios of the final end of human history, often in religious contexts.
World history is commonly understood as spanning the major geopolitical developments of about five millennia, from the first civilizations to the present.
World population is the sum of all human populations at any time; similarly, world economy is the sum of the economies of all societies (all countries), especially in the context of globalization. Terms like world championship, gross world product, world flags etc. also imply the sum or combination of all current-day sovereign states.
In terms such as world religion, world language and world war, world suggests international or intercontinental scope without necessarily implying participation of the entire world.
In terms such as world map and world climate, world is used in the sense detached from human culture or civilization, referring to the planet Earth physically.