For example i did read wikipedia today on BOM definition but i didn't understand why this is usefull to exist and actually what is it anyways.
Quote previously linked document (emphasis mine): While UTF-8 does not have byte order issues, a BOM encoded in UTF-8 may nonetheless be encountered. A UTF-8 BOM is explicitly allowed by the Unicode standard, but is not recommended, as it only identifies a file as UTF-8 and does not state anything about byte order."
Also i don't undersand the different between ANSI(which you told me this sitn an encoding) to utf8 and why the remote webserver has trouble idntifying anythign else than ANSI.
They're both character encodings, but different encodings.