Looking up the documentation for some command/function or configuration option/variable is something all Emacs users have to do quite often. Two of the Emacs help commands that I use most often are describe-function (C-h f) and describe-variable (C-h v). Basically they display the documentation for some function or variable. E.g. if you press C-h f and type afterwards describe-function we’d get the following:

describe-function is an autoloaded interactive compiled Lisp function in

It is bound to C-h f, <f1> f, <help> f, <menu-bar> <help-menu> <describe>

(describe-function FUNCTION)

Display the full documentation of FUNCTION (a symbol).
When called from Lisp, FUNCTION may also be a function object.

See the ‘help-enable-symbol-autoload’ variable for special
handling of autoloaded functions.

Probably introduced at or before Emacs version 22.1.

describe-variable is also useful to check the current value of some variable. Here’s an example:

clojure-indent-keyword-style is a variable defined in ‘clojure-mode.el’.

Its value is ‘always-align’

I’m guessing most Emacs users are quite familiar with both commands. What I didn’t know until recently, though, is that Emacs 25.1 introduced the related command describe-symbol (C-h o), which works for both functions and variables. I’m guessing most people would benefit from using it over the more specific commands, as it reduces some mental overhead. (the fewer keybindings we have to remember, the better)

Bonus points - describe-symbol also works with faces, so it’s a good replacement for describe-face (which doesn’t have a default keybinding). One command to rule them all!

That’s all I have for you today. Keep hacking!