Role (noun)

1. The function assumed or part played by a person or thing in a particular situation.
2. The actions and responsibilities of a particular person or group.

Origin:

Late 16th century (in the sense "character played by an actor"): from french rôle, from italian ruolo, based on latin rotulus "rolling (book or document)", from rota "wheel".

Examples:

1. He has a key role in the company.
2. She played the role of the mother in the play.
3. The role of government in society is a hotly debated topic.
4. He took on the role of CEO.
5. The role of technology in education is constantly changing.