There are two ways to easily determine which version of Apache you are running. You can either use the command line from a terminal program or if Apache is running you can use the web browser on your server!

From the Command Line:

Run httpd with the -v or -V option. To do this type the following at the command prompt:

httpd -v

Or if you use httpd -V (as shown below) the output will show you where all of Apache's configuration files are located.

httpd -V 

If you don't get any result or "command not found" then you have Apache 2 and you will need to run apache2 -v instead. See below:

apache2 -v 

Using the web browser on your server:

Open the web browser on your server and go to this URL: http://localhost/manual/

That should show you the locally installed manual pages which indicate the version at the top.

(Note: You could also use http://127.0.0.1/manual)