Oh, I would never consider myself a webmaster. I am just a C/C++ programmer who stumbled across PHP from another one of my C++ buddies. It was PHP that really forced me into learning HTML. Hell, I still don't know HTML that well. I am by no means a web designer. I still have to look up <form> tag options. With PHP eventually comes MySQL, which forces you to learn SQL.
It definitely helps to have a programming background if you are going to learn PHP. Anybody can learn the syntactical side of a language real quick. The real help comes from programming practice, concepts, and approaches to problems.
Stick with it, you will be at an advanced level in no time. You just have to do it, you can only learn so much from reading.
The primary purpose of the DATA statement is to give names to constants; instead of referring to pi as 3.141592653589793 at every appearance, the variable PI can be given that value with a DATA statement and used instead of the longer form of the constant. This also simplifies modifying the program, should the value of pi change.
-- FORTRAN manual for Xerox Computers