Function: show-paren-mode

Toggle visualization of matching parens (Show Paren mode).
With a prefix argument ARG, enable Show Paren mode if ARG is
positive, and disable it otherwise. If called from Lisp, enable
the mode if ARG is omitted or nil.

Show Paren mode is a global minor mode. When enabled, any
matching parenthesis is highlighted in `show-paren-style' after
`show-paren-delay' seconds of Emacs idle time. (fn &optional ARG)

Variable: show-paren-mode

Non-nil if Show-Paren mode is enabled.
See the command `show-paren-mode' for a description of this minor mode.
Setting this variable directly does not take effect;
either customize it (see the info node `Easy Customization')
or call the function `show-paren-mode'.