Linux file permissions issue, unexpected access to file-Collection of common programming errors

I’m relatively new to Linux so please excuse my ignorance.

I have a public web directory where I have been experimenting with the permissions to try to learn about them. I have set up a simple test.php file and set its permissions as follows:

-rw — —

Which I was expecting to mean only the owner can access the file and no other. But, I can still access this file remotely from the web and the test page shows? This is on a Red Hat web server. NOTE: The owner use is not the web access user.

This worries me as I then think maybe a web user could write to the file some how (is it possible?).

Any pointers would be great. I just want to makesure I understand this as it seems to me to be an important security concept.

Cheers C