功能變數名稱,(它將INTERNET上的IP位址,用文字表示。假設IP地址是一個人的身份証號碼,那?,功能變數名稱就是一個人的名字[但該名字唯一])
domain name n : strings of letters used to name organizations and computers and addresses on the internet; "domain names are organized hierarchically with the more generic parts to the right"
domain name {fully qualified domain name}