I've dumped hexadecimals of a text using windows debugger. So if those hexa values represent every single character by a single hex value,does it mean its binary is that hexa's converted binary value and pc deals with that character using binary but assembly language and people convert and use it as hexa because it is easy to use?
tell me if you don't understand what am i asking clearly

Yes, that's exactly it.
The HEX values fit in a two-place format, so they are easier to read.
More can be represented in a small space than with decimal or binary.