A more thorough explanation:

Definition: A councillor is a person who serves on a council, especially at the local level. It can also be spelled as councilor.

Examples:

• John was elected as a councillor for his local town council.
• The council held a meeting to discuss the new budget with the councillors.
• As a councillor, Sarah is responsible for representing the needs and concerns of her constituents.

The examples illustrate that a councillor is someone who is elected or appointed to serve on a council, which is a group of people who make decisions and policies for a particular area or organization. Councillors are responsible for representing the interests of their constituents and working together with other councillors to make decisions that benefit the community.