This is a simple online bold text generator. The bold text that is generated is actually a set of symbols from the Unicode symbol set. Many of these symbols are supported by modern browsers and so you should be able to copy and paste the formatted text into facebook (e.g. for your fb name), twitter, instagram, tumblr and other social media posts and statuses.
You might have initially thought that this converter generates a bold font, but this is not the case. Fonts cannot be copied and pasted, whereas the special characters that this translator creates can indeed be copied into your username or nickname or blog posts or wherever so that it is more noticable than others.
The lower case and upper case bold alphabets from unicode are: