Object not found! 404 error

Can't access any files (in folders) directly in browser. Why?

I get a 404 error.

For example, if I try to navigate to http://ift.tt/1i67BtL then the image file name ... it display s a 404 error.

I'm just curious if this normal? Or is it a block on my server?

I created a simple php file and added it to one of my plugin folders. Then I tried to simply navigate to that php file in the browser. But it displays a 404 error.

So .. I'm just curious if this is the way things "should" behave, or if something needs to be changed to allow php files (in my plugin folders) to be accessible from the browser (or is this a security issue).

I'd appreciate any input or comments.

Thanks