(?s)applies the following effective flags to the remainder of the pattern: gms s modifier: single line. Allows a dot to match line terminators
<div class="the literal text <div class=" (case sensitive) Group 1(data|plainText|extData) datathe literal text data (case sensitive) plainTextthe literal text plainText (case sensitive) extDatathe literal text extData (case sensitive) \s*any whitespace character, repeated any number of times
.*?any character, repeated any number of times
\s*any whitespace character, repeated any number of times
<the literal < (6010 / 748 / 3C16)
\/the literal / (4710 / 578 / 2F16)
div>the literal text div> (case sensitive) g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string