\ban ASCII word boundary
abthe literal text ab (case sensitive) \w*any word character, repeated any number of times
\W*any non-word character, repeated any number of times
\sany whitespace character
andthe literal text and (case sensitive) \ban ASCII word boundary
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