It's a very common root and appears in many English words, often indicating a relationship or action involving two or more things.
Here are some examples:
* Interchange: To exchange things between people or groups.
* Interfere: To get involved in something that does not concern you.
* Intermission: A break between parts of a performance.
* International: Involving two or more countries.
* Interact: To communicate or react with one another.
Understanding the meaning of "inter" can help you decipher the meaning of many English words.