Subpatterns and alternative patterns

Question 0

(?:…)

Answer 0

Non-capturing group - group subpattern, but don’t capture the match. Example: (?:foo)bar matches foobar and doesn’t capture anything

Question 1

(…)

Answer 1

Capturing group - group subpattern and capture the match. Example: (foo)bar matches foobar and captures foo

Question 2

…|…

Answer 2

Alternation operator - matches one of the alternative subppatterns. Example: foo|bar|baz matches either foo, bar or baz