Shortcodes in WordPress lets you add functionality to your posts, pages, widgets, without actually writing any code. There are many WordPress themes and plguins that offer shortcodes to add different elements to your page like pricing, events, etc into WordPress.
ShortCodes in WordPress makes it easier to add elements to your post like adding a responsive slider by just using a simple shortcode. You can also create a simple survey form in WordPress with just a single line of shortcode.
This eliminates the need for copying and pasting codes from other sites, or repeating a tedious task all over again.
Here are some tips when using shortcodes: http://www.wpbeginner.com/beginners-guide/7-essential-tips-for-using-shortcodes-in-wordpress/