Let's look at some examples. Combining expressions like this can get very complicated very quickly. There have to be as many 'close' parentheses as there are 'open' parentheses. The real power of Perl comes from its extensive use of regular expressions. Regular expressions allow us to look for text 'strings' within larger text documents or in lines of text.
Regular expressions occur between two forward slashes.
The simplest form of a regular expression is just to put the text you're looking for between two slashes. We'll find Amy in the line of text whether her name is given as 'Amy', 'amy', or 'AMY'. This format you've already seen. This is useful, but it is only the tip of the iceberg of the power of regular expressions. You can also use 'wildcards', like the wild cards that the Unix shell uses, to fudge your comparison.