Question: what is the difference between add_action and add_filter in wordpress?
Answer: 1 Answer. add_action is what you use to create a trigger “hook” – when something happens, do-something-else. add_Filter add_filter is used to “hook” data change/replace – where there is [some-code], change it to some-other-expanded-code. ... A plugin can modify data by binding a callback to a filter hook.