Port 80 is the default port for the server to receive HTTP communication. Apparently you have another server installed on your computer that already uses this port. You have two options:
As indicated by Gemasoft in its response, you can search the process of the application (the process of the other web server) and close it. Thus, when you raise your Apache server you can run without problems since port 80 is free.
Change the port used by any of these applications. In this case, I would change the Apache port so that instead of pointing to port 80 it points to a different number. The port number can vary between 0 and 65536. Choose a number other than 80, for example 4000. In Apache, you can change the port number by modifying the link file that should be found in <ruta_instalación_xampp>/apache/conf ( <ruta_instalación_xampp> is usually C:\xampp , in my case it is not, so its value depends on the path where you have installed xampp) and look for the following lines:
Listen 80
# más líneas...
ServerName localhost:80
Change the number 80 to the port number you want. For this example, it would be 4000.
Listen 4000
# más líneas...
ServerName localhost:4000
As Apache is being raised by XAMPP, I recommend that you go to the Control Panel and select the Config option. In the window that appears, select the Ports and Services Configuration option. In the window that appears, select the tab Apache and change the main port to 4000. I leave the image as a reference:
Now start your Apache server. I should run without problems. To access it and verify that it is running without problems, go to the following url:
link
(Note that now we have to indicate the port in the URL, since 80 is the default port, when you access http://localhost/ it's as if you access http://localhost:80/ )
In case you do not want to change the Apache port, you can choose to change the port of the other application that uses port 80.
If you are in a controlled environment, say your personal work computer, and this is simply for learning, you can use the first option if you do not need the other application, and if you want both to live together you can use the second option. If you are in a slightly controlled environment where you only have control over Apache, I recommend the second option. If it is a production server, I would ask why you have another application that already listens to port 80 and would analyze the situation.
