Really dumb question: What is a “backtick” for code in posts? How to type one?

Trying this too…

strongThis is boldstrong

????? Geeez…

Trying again BOLD

The “backticks” are supposed to be used for preventing code to be rendered; e.g.
<a href="something">link</a>
as opposed to link

The two lines above are identical, but the first one has backticks ` around it.

I haven’t posted before, and I don’t quite understand the backticks thing, and I can’t think of a better place to test it.

Here we go.

<?php

if (is_category('xyz')) {

        Do something;
        }
elseif (category('xyz2')) {
        Do something else ;
        }
elseif (category('xyz3')) {
        Do something else;
		}
else {
        Do something if none of the above are true;
        }
?>;