Do you know the meaning of idiom "car pool"?

To "pool" resources is to share something(s) amongst 2 people or more for the cost or efficiency saving benefit of all the sharers. To share a car to get to work (for example) is to "car pool" where 2 or more people get together to travel in a car to a common destination. The pengers may contribute money for fuel as their part of the resource sharing. The driver provides his/her car and the driving service (ncluding possibly collecting the people) The people may also take turns in using their own cars to carry each other on other trips to and from the destination as mutually agreed.