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= Log4j API

Log4j is essentially composed of a logging API called *Log4j API*, and its reference implementation called *Log4j Core*.

.What is a logging API and a logging implementation?
[%collapsible]
====
include::partial$concepts.adoc[tags=inc;api;impl]
====

[TIP]
====
Are you looking for a crash course on how to use Log4j in your application or library?
See xref:manual/getting-started.adoc[].
You can also check out xref:manual/installation.adoc[] for the complete installation instructions.
====

Starting with version `2.24.0`, Log4j API is embraced as the target logging API for both Log4j 2 and Log4j 3.
Hence, **Log4j 3 does not contain a Log4j API module**, but instead implements _"the"_ Log4j API developed in Log4j 2 branch.
This ensures Log4j 2 users can safely migrate to Log4j 3 without any Log4j API compatibility concerns.

{log4j2-url}/manual/api.html[Read more on Log4j API in the Log4j 2 website...]
