{bold} is specifically about making document elements bold (or removing this font attribute). For general questions about formatting document elements, use {formatting} instead.
bold is specifically about making document elements bold (or removing this font attribute). For general questions about formatting document elements, use formatting instead. For blackboard bold letters or symbols in mathematics, use blackboard.
There are several different ways to get bold text in LaTeX; see this question for discussion on when to use the different bold commands.
\textbf{...}will make text inside it bold.- The
\bfseriescommand switches on bold text, which is useful for defining formatting, e.g. when using the listings package. \mathbf{...}will make Roman letters inside of it bold: to bold other characters, there are several different options discussed in this question.\bfis deprecated. Don't use it.
