问一个关于package依赖方案的问题

{ "name": "blog", "version": "0.0.0", "private": true, "scripts": { "start": "supervisor ./bin/www" }, "dependencies": { "body-parser": "~1.13.2", "connect-flash": "0.1.1", "connect-mongo": "^0.7.0", "cookie-parser": "~1.3.5", "debug": "~2.2.0", "ejs": "~2.3.3", "express": "~4.13.1", "express-session": "^1.9.1", "mongodb": "2.0.52", "mongoose": "4.3.0", "morgan": "~1.6.1", "serve-favicon": "~2.3.0" } } 我的疑问就是那个mongodb版本是数据库的版本，还是什么驱动的版本，我执行install之后是安装了个数据库还是？ 小白一枚...求指点。