\ban ASCII word boundary
\w{4,}any word character, repeated at least 4 times
\ban ASCII word boundary
\ the literal (3210 / 408 / 2016)
bthe literal b (9810 / 1428 / 6216) (case sensitive)
\w{4,}any word character, repeated at least 4 times
\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