The term 'Espresso Server' is a job title for a Barista, which is someone who prepares and serves coffee drinks. A Barista is responsible for operating espresso machines, grinding coffee beans, and creating coffee drinks such as cappuccinos, lattes, and macchiatos. They must also be knowledgeable about the different types of coffee beans and brewing methods. Additionally, they must be able to provide excellent customer service and maintain a clean and organized work area.