Log on to Admin => Site => Global Settings, you will get to the "Global settings" page appeared. By default the Global settings option is only available to administration users with the right 'Administrator' or "Super Administrator". It can be used to adjust certain settings of entire application in a al context.

In short, Global settings define a mechanism for storing configuration data used in the application settings architecture. Once you enter value to the Global settings page and saved, then the values will be overruled by the settings in the Global settings. Below is a description of each tab of the general config to aid in finding what you need.
 

Settings and their explanation
 

Site Configuration
 

The most importantly Site configuration section under the Global Setting is to customize site’s Title, Name, Country, Currency, language and other SEO related setting. According to the given value, the entire application will be rendered and every modules and sub-modules will follow this instruction added here.