什么是 database？
A container (usually a file or set of files) to store organized data.
database是存放数据的_容器_。
Database Management System (or DBMS)
database 不等同于 database software。database software 叫 Database Management System，简称 DBMS。
SQL
SQL (pronounced as the letters S-Q-L or as sequel) is an abbreviation for Structured Query Language. SQL is a language designed specifically for communicating with databases.
SQL是一种_语言_，专门为数据库之间的communication设计，大部分数据库软件都支持SQL。