\defgroup IO Input/Output Library

The library collecting the ROOT classes dedicated to data input and output.

For an overview of I/O in ROOT, see the following pages in the ROOT manual:

- [ROOT files](https://root.cern/manual/root_files)
- [Trees](https://root.cern/manual/trees/): ROOT's columnar storage
- [I/O concepts](https://root.cern/manual/io/): a collection of more advanced I/O-related topics
- [I/O of custom classes](root.cern/manual/io_custom_classes/): how to read and write user-defined C++ objects

For ROOT I/O developers, a detailed internal description of the \ref rootio is also available.
