If you want to quickly know how to use PaddlePaddle, please refer to the following guide:.. toctree:: :maxdepth: 1 quickstart_en.rstWhile using PaddlePaddle to build applications, please understand some basic concepts.Here is an example of linear regression. It introduces workflow of PaddlePaddle, including data format, model configuration and training, etc... toctree:: :maxdepth: 1 concepts/index_en.rst