^start of line
https://wwwthe literal text https://www (case insensitive) .any character (except for line terminators)
instagramthe literal text instagram (case insensitive) .any character (except for line terminators)
com/the literal text com/ (case insensitive) \w+any word character, repeated at least once
/the literal / (4710 / 578 / 2F16)
\w+any word character, repeated at least once
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
i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters