When a module is published to the environment it is stored in the Public Area, and all changes become public to other developers.
For example, if you change a screen and publish the module, other developers working on that module will have to merge their work with your changes. Also, developers executing the application will start using the screen with your changes.
Using the Public Area
A module is always updated in the Public Area through the 1-Click Publish. This operation generates a new version of the module and stores it in the environment, thus allowing you to have version control. Any new version of a module becomes available to other developers working on the same module.
Learn more Execute a Module in the Public Area and About Working in Teams.
Impact on the Personal Area
The database is shared, therefore, changing database data or schema will affect all developers, including the ones using their Personal Area.
Learn more About the Personal Area and About Working in Teams.
About Working in Teams | Execute a Module in the Public Area