php+mysql+apache是什么，做什么用的

php：基于服务端来创建动态网站的脚本语言
http://zhidao.baidu.com/question/949887.html
mysql：数据库
http://zhidao.baidu.com/question/9151159.html
apache：http服务器
http://zhidao.baidu.com/question/10967011.html

网页格式+数据库和管理！

php: preprocessor server page, an server-side scripting technique, which is like jsp, asp.
mysql: a fast and powerful database management system. It's like oracle 9i.
apache: a http server. If you want to create internet pages which can be browse by others, you are supposed to be build a server in your machine and have a stable connection to internet.

We often refer them as LAMP(Linux + Apache + MySQL + PHP). The whole system can be build to install a web application which links web page(http), server page(php) and database(php) together.