When PHP come into the word, the Internet world seems to have found a relatively perfect alternative to a website development language in an ever-growing technological age. We use this language to develop website everyday. But with the neophyte, HTML 's definitions and operational mechanism of PHP, not everyone can explain clearly and specifically.
HTML concept
HTML (HyperText Markup Language) is one of the languages used in web programming. When visiting a website, specifically clicking on links, you will be directed to many different pages, and these pages are called an HTML document (HTML file).
Overview of HTML
An HTML page is made up of many small HTML elements and specified by tags. You can distinguish a website written in HTML or PHP language through its link. At the end of the HTML pages, there are often tails of .HTML or .HTM
HTML, in its true meaning, is a hypertext markup language, so its functions revolve around this element. Specifically, HTML helps to constitute the basic structure on a website (dividing the frame, layout of website components) and contributing to support the declaration of digital files such as videos, music and images. The strength of HTML is its ability to build structures and make web pages go to a method, simultaneously become a complete system. If you want to own a well-structured website that aims to use a variety of elements in text, ask HTML. In fact, HTML contains essential elements that no matter what kind of website our website is, what programming language we communicate to handle data, it still needs HTML language to display content for visitors.
HTML is a simple web programming language. Every web page, every web browser can display HTML well. Currently, the latest version of HTML is HTML 5 with more good features and quality than the older HTML versions.
PHP concept
PHP stands for "Hypertext Preprocessor", previously Personal Home Pages. This is a programming language used to write on the server side (web programming). Currently, there are many languages for writting in servers such as C #, Java, Python and PHP as one of the languages of this group.
Overview of PHP
A PHP file consist of PHP tags and ends with the ".php" extension. Only the server that has installed PHP can interpret PHP scripts. Clients accessing PHP scripts will only require a web browser. Besides, PHP's syntax is similar to C and Java, so programmers can learn and build a product that is relatively fast in comparison with other languages.
PHP code can also be embedded into HTML code and pages easily, or used in conjunction with various web template systems, web content management systems and web frameworks.
PHP is very suitable in writing for the web. It has a simple, fast and compact syntax, easy to learn and time to access PHP shorter than other programming languages, so PHP currently accounts for a relatively large number of programmers, maybe called the biggest. At now, PHP has many open source code (CMS) such as WordPress, OpenCart, NukeViet, … so it is very diverse and adapts most common websites from personal blogs to websites to introduce companies and sales.
Currently the highest version of PHP is PHP7, this is a jumpy version because PHP updated many features to help programmers have more choices. The versions of PHP3 and PHP4 we should not discuss because most servers do not have it installed, which means that currently servers only install PHP5 and PHP7.
Different between Operation of HTML and PHP
To understand the operation mechanism of HTML and PHP is completely different. First of all, you need to know a concept: client-server relations. This relationship takes place when someone visits our site, after they type in the address bar, enter, then the web page is downloaded and displayed on the screen! It's perfectly reasonable, but in the middle of the time after they enter and when the website shows up, what happened in this mechanism? Client means a user, accessing a website through a website address. All web viewers refers to clients.
Server (server): It have only one server. Placing somewhere in the world, the server is a huge, 24-hour networked device (with an extremely fast connection speed), it not only run alone 24 hours a day, but also no one touches, nobody plays anything on it. It only does one task that is to distribute web pages to clients
Server is a computer but there is no screen, because screen is unusable for anything in this situation. Sever’s mechanism is that it contains any web page on hard drive, every time a client accesses web page, it sends the web page to that person.
In the Internet environment, the huge, non-screen giant server works continuously and constantly whenever someone accesses a web page and sends it to clients.
After understanding the client-server relationship. Let's now explore how PHP and HTML work differently.
Firstly, about HTML:
1. The operation process after we access an HTML website have two steps:
2. Client (user) wants to access, view a website. User sends request to server through accessing website address. Let's imagine as: “Server, please send me page example.html”
3. Server responds by putting the website displayed on your screen “Here! This is the website you have just asked to see”
Now to PHP:
It inserts another step between the two steps above, the PHP page is generated by the server before being sent to the client.
The operation steps are as follows:
1. Client sends request through accessing website: “Server, please send me the example.php page”
2. Here, a very important step, the server does not send the website to the client immediately, but it generates the website first. So the client cannot read the php page with anything in it (only the server can read it), the client can only read HTML pages. The server's task is very simple: it transforms the php page into an html page so that the client can read it.
3. Finally, after creating the HTML page, it only has HTML code inside, the server send it to the client: “Here! This is the site you want to see”
