This and that are demonstrative pronouns. They are used to point out specific things in the world. This is used for things that are close to the speaker, while that is used for things that are farther away.

All languages have words for this and that because they are essential for communication. We need to be able to point out things in order to talk about them. Without words like this and that, it would be very difficult to have a conversation.

In some languages, there are even more than two demonstrative pronouns. For example, in Spanish, there are three demonstrative pronouns: este, ese, and aquel. Este is used for things that are close to the speaker, ese is used for things that are farther away but still visible, and aquel is used for things that are far away and not visible.

The existence of demonstrative pronouns in all languages shows that they are an important part of human communication. They allow us to point out things in the world and to talk about them. Without words like this and that, it would be much more difficult to communicate.