Apache is the most popular web server software in the world. It runs 67% of the servers in the world, including the one that hosts this very site. Part of the reason why, is because it is open source and 100% free to use for anyone, just like WordPress.
It is a reliable, secure, fast & highly customizable tool, that you can extend and customize to create many different kinds of environments. An example of these extensions is PHP & databases like MySQL, which WordPress and other CMS need to be able to function.
What Is Web A Web Server?
But before we can understand what Apache is, we have to answer the question; what is a web server anyway?
Web Servers interact with web browsers (like Chrome, Firefox and Edge) to allow you remote access to data & functions. Accessing a web server from your own computer is kind of like making a call to customer service to ask for information or some help.
Your web browser is the phone, the internet is the line & the web server is the customer support rep on the other side.
First of all, he will listen to your questions (requests), and then he will give you tell give you the information you requested (at least hopefully.)
The way the browser “makes the call” and the web server receives it is through something called the HTTP protocol. First, the browser sends a HTTP request to request access to certain files, then the web server checks the request, and if it clears, you can access the files in question.
The process looks something like this:
If this process of receiving requests and serving files is the only thing server can do it’s called a static web server.
Dynamic Web Servers
In the case of more complex files (like the PHP files in WordPress) it will also need to recruit the necessary modules to create the right environment for displaying the page in your web browser. WordPress doesn’t create hundreds and hundreds of files on your server, it uses a database to store info and then dynamically generates & serves pages later. (Much like a customer support rep might talk to technical staff for complicated issues.)
A set up that allows the running of more complex files (files that your browser can’t run as they are) is called a dynamic web server. WordPress & most content management software needs dynamic web servers to be able to run properly.
A dynamic web server will function more like this:
And that is the point of Apache, to create environments like this.
That way you don’t have to have an uncountable number of text/html files on your server. You can store most of the relevant data in quickly searchable databases. This also avoids waste, as you can re-use the most common elements on every single page. (Like with WordPress templates, that decide the look of every single generated static html file.)
So people all around the world use Apache to set up dynamic web servers like this. And because of it’s capabilities, they can run many kinds of cool software.
Apache isn’t the only alternative that can run software like WordPress on your server. There are many other alternatives, like nginx, but it is the most common by far.