This is probably a beginner question, but it's always been throwing me off about LaTeX, especially because when I'm showing new people the basics, I can't explain why that is.
So the question is: Why does \large have to be wrapped inside {} to not make everything after it become large as well? When I type \large{Some text} it doesn't mean at all what one might expect ({Some text} isn't an argument apparently). For commands like \textbf it works the way I'm used to for most commands: Without braces, it just affects the next token, with curlies, it affects that whole argument inside the curlies and nothing beyond that.
Is there a term for these kinds of commands? I don't recall having seen very many others that behave like this.
\largeis a font size declaration which is active until another font size declaration appears or the local group ends. In fact,\largedoes not have an argument, so\large{foo}is actually wrong but does not really do harm – Apr 14 '17 at 23:33\textbf{...}is just a convenience function, because you often only want to typeset a few words in bold. The command that does the work is\bfserieswhich is like\largestays in force until it is cancelled. See https://en.wikibooks.org/wiki/LaTeX/Fonts for a longer list of similar macros. – alephzero Apr 14 '17 at 23:42\TeXand\LaTeXcommands - it's nothing special to do withtextbf. – alephzero Apr 14 '17 at 23:46\largecan be considered like the speed limit sign on a road: The speed limit on it usually holds until the next speed limit (either lower or higher) appears... – Apr 15 '17 at 00:10\bfseries,\color{red},\sloppy,\raggedright,\largeare all declarations that affect all following text until the end of the current group – David Carlisle Apr 15 '17 at 00:11