Explaining #log4j for non technical people, because the internet is burning down and y'all might want to know what's happening and why there's all this "${jndi:ldap" stuff out there
Log4j is a popular logging library used in Java programming language.
A logger is a piece of software that saves data on a computer. It is used to monitor what is happening, determine if the software runs smoothly, or catch information to help debugging when things go wrong.
It logs a lot of information. When you browse to a website, it will write down what IP address you have, what browser you are using (firefox, chrome, edge... ), when you made the request, what page you accessed... and more!