root user is the system the only super administrator, it has the authority equivalent to the operating system. Some applications that require root privileges, such as ad blocking, that requires root privileges. The problem is bigger root system administrators the ability to windows than enough to put most of the file deleted the entire system, causing the system completely destroyed and can not be used again. Therefore, improper operation with root is quite dangerous, minor crashes can be serious and even not boot. So, in Unix, Linux and Android, unless really necessary, under normal circumstances do not recommend using root. Best to establish a single common user, as a daily use.
Some tasks can only be executed by the root, such as deleting system built-in applications. But it does not recommend the use of root in a Unix or Linux system, which constitutes a contradiction. So have a sudo approach is to use su to mention the right, if necessary, that is part of system administration privileges granted to ordinary users, and only when the user needs elevated privileges, these users are allowed to use a temporary root command to manage the system.