The world is the planet that we live on.

The world refers to all the people who live on this planet, and our societies, institutions, and ways of life.

You can use world to describe someone or something that is one of the most important or significant of its kind on earth.

You can use world in expressions such as the Arab world ,the western world, and the ancient world to refer to a particular group of countries or a particular period in history.

Someone's world is the life they lead, the people they have contact with, and the things they experience.

You can use world to refer to a particular field of activity, and the people involved in it.

You can use world to refer to a place or way of life by describing its strongest features.

You can use world in expressions such as this world ,the next world, and the world to come to refer to the state of being alive or a state of existence after death.

You can use world to refer to a particular group of living things, for example the animal world ,the plant world, and the insect world.

A world is a planet.

If you say that two people or things are worlds apart, you are emphasizing that they are very different from each other.

If you say that someone has the best of both worlds, you mean that they have only the benefits of two things and none of the disadvantages.

If a woman brings a child into the world, she gives birth to it.

If you say that there is a world of difference between one thing and another, you are emphasizing that they are very different from each other.

If you say that you would not do something for the world, you are emphasizing that you definitely would not do it.

If you say that something has done someone the world of good or a world of good, you mean that it has made them feel better or improved their life.

You use in the world to emphasize a statement that you are making.

You can use in the world in expressions such as what in the world and who in the world to emphasize a question, especially when expressing surprise or anger.

You can use in an ideal world or in a perfect world when you are talking about things that you would like to happen, although you realize that they are not likely to happen.

If you say that someone thinks that the world owes them a living, you are criticizing them because they think it is their right to have a comfortable life without having to make any effort at all.

If you say that someone is a man of the world or a woman of the world, you mean that they are experienced and know about the practical or social aspects of life, and are not easily shocked by immoral or dishonest actions.

If you say that something is out of this world, you are emphasizing that it is extremely good or impressive.

You can use the outside world to refer to all the people who do not live in a particular place or who are not involved in a particular situation.

If you say that something happens or exists the world over, you mean that it happens or exists in every part of the world.

If you say that someone is in a world of their own, you mean that they seem not to notice other people or the things going on around them.

If you think the world of someone, you like them or care about them very much.

If you say that someone has gone up in the world, you mean they have become richer or have a higher social status than before. If you say they have come down in the world, you mean they have become poorer or have a lower social status.