Question about php files

[ttb]

Am i correct in stating that every time I encounter a file I want to edit that ends in .php, I want to make sure it is a file that is in my "CUSTOM" folder?

also, am I correct in stating that I should NOT edit the file in the admin/tools/define pages editor, NOR should I edit the files in cPanel's editor? I should only edit the files in a program like notepad++ or crimson editor?

thanks everyone

[kobra]

Am i correct in stating that every time I encounter a file I want to edit that ends in .php, I want to make sure it is a file that is in my "CUSTOM" folder?

Anywhere there is a classic folder - the files directly in that folder can be placed in an override folder i.e. custom or your template folder name

also, am I correct in stating that I should NOT edit the file in the admin/tools/define pages editor, NOR should I edit the files in cPanel's editor? I should only edit the files in a program like notepad++ or crimson editor?

Correct on cPanel's editor, but the Zen Cart editor is fine but will only load pre-defined files.