What is the difference between a closely held corporation and a publicly held corporation?

What is the difference between a closely held corporation and a publicly held corporation?
A closely held corporation does not have its stock available for the public to buy and be a part of. Stocks in these kind of companies are kept in small circles of people related to the company's owners.

A publicly held corporation trades its stock over a stock market and anyone (with sufficient funds) is able to buy, trade, and sell that company's stocks.