A more thorough explanation:

A stockjobber is a middleman in the exchange of securities among brokers. They buy and sell stocks on behalf of others, usually for a commission.

For example, if a broker wants to buy 100 shares of Apple stock for their client, they may go to a stockjobber who has access to the stock exchange and can make the purchase on their behalf. The stockjobber may charge a fee for their services.

Another example of a jobber is a wholesaler who buys products from a manufacturer and sells them to a retailer. For instance, a clothing manufacturer may sell their products to a jobber who then sells them to a department store.

Overall, a stockjobber is a type of middleman who facilitates the buying and selling of securities among brokers.