Apache logs are files that record everything the Apache web server is doing for later analysis by the server administrator. The records of all Apache events are placed in two different text files:

• Access Log: this file stores information about incoming requests. You’ll find details about each request such as the requested resource, response codes, time taken to generate the response, IP address of the client, and more.
• Error Log: this file contains diagnostic information about any errors were encountered while processing requests.

The log files’ location depends on the operating system the Apache web server is running. On Debian-based operating systems like Ubuntu, the access log file is located in /var/log/apache2/access.log. On CentOS, RHEL, or Fedora, the access log file is stored in /var/log/httpd/access_log.

Similarly, the error log file is located in /var/log/apache2/error.log on Debian-based systems and /var/log/httpd/error_log on CentOS, RHEL, or Fedora. A typical error log entry might look like this: