How Do Filters Work In WordPress

The idea of filters and actions still unclear to me. I decided to solve this problem once and for all. I'll share with you what I found out about WordPress' filters. The first one is a tag and the second is a function. Add_filter accepts two parameters: tag and function. When apply_filters run on a particular tag, it will call all functions that added to that tag. You can add as many functions to a filter tag as many times as you like.