Bash Shell Scripting - String Comparison Operators

The video tutorial covers string comparison operators, starting with an introduction to the concept. It explains how to declare variables and use the if block to compare strings. The tutorial demonstrates checking if a string is null or non-null, using operators like '-z' and '-n'. The video concludes with a summary of the techniques discussed.

Describe the process of checking if a string is not null as mentioned in the text.

How can you compare two strings directly using variables according to the text?