| . Remember from the HTML section that it is one of | | | | This is an important aspect that differs PHP/mySQL |
| the core parts of an HTML document. In this way | | | | from the other languages. PHP/mySQL are run from |
| you can think of the as the top of the tree. If you | | | | the server, or the computer that your computer |
| place an element in the body it is like a branch | | | | downloaded a web site from. HTML/CSS/JavaScript |
| coming from the top of a tree to that element and | | | | are run after the files have been downloaded to your |
| connecting it. Now that there is this connection you | | | | computer by your computer via the browser. |
| can use JavaScript to be able to change whatever is | | | | This connection has many important and difficult |
| at that branch. | | | | implications. One is that you only have one shot at |
| The language itself is very similar to c and is fairly | | | | downloading content from a server. After the page |
| easy to learn. What is difficult is understanding how | | | | has been downloaded to download something else |
| to navigate around the DOM to make dynamic web | | | | you have to reconnect to the server to get fresh |
| pages. | | | | content. There are a few ways to do this, either |
| PHP & mySQL | | | | requesting a new page or by using JavaScript. |
| With the understanding of HTML/CSS/JavaScript it is | | | | Review |
| possible to make interactive websites. But what if | | | | Some final terminology is backend vs. frontend. |
| you want to be able to save content that is | | | | Frontend is what is being processed by a host (your) |
| provided by a viewer of your site, i.e. a comment. | | | | computer via the browser. This is done with HTML |
| The most basic use of PHP is to get content | | | | CSS/Javascript. You have gone to a url and a server |
| submitted from an HTML site and put it into a | | | | (computer) has sent you some documents. Your |
| mySQL database. | | | | browser looks at these documents and figures out |
| A database is like an excel spreadsheet, or a bunch | | | | what they say (HTML) and how to make them |
| of rows and columns that are able to hold many | | | | appear(CSS). If it wants to make the content move |
| types of information. PHP and mySQL are the most | | | | around it will use JavaScript. |
| common and free combination of script/database | | | | The backend is everything the server can do, this |
| languages on the web right now. | | | | includes providing the HTML/CSS/JavaScript |
| PHP is considered a scripting language. This is because | | | | documents to sending off email. This is done via PHP, |
| it is not compiled, i.e there is no .exe or executable | | | | and if any content is to be stored it is stored using a |
| like if you are running a program on your desktop. | | | | mySQL database. |
| Instead when a website needs something to happen | | | | Hopefully this will have provided a basic understanding |
| it calls a PHP script which is immediately interpreted | | | | of the different languages and aspects of a website. |
| by the server that is hosting the website. | | | | |